query: a gene on the y chromosome that determines maleness is

pos: Y chromosome Y chromosome The Y chromosome is one of two sex chromosomes (allosomes) in mammals, including humans, and many other animals. The other is the X chromosome. Y is the sex-determining chromosome in many species, since it is the presence or absence of Y that determines the male or female sex of offspring produced in sexual reproduction. In mammals, the Y chromosome contains the gene SRY, which triggers testis development. The DNA in the human Y chromosome is composed of about 59 million base pairs. The Y chromosome is passed only from father to son. With a 30% difference between humans

pos: Sex-determination system they're created; in others, however, such as fruit flies, sexual differentiation occurs as soon as the egg is fertilized. Some species (including humans) have a gene SRY on the Y chromosome that determines maleness. Members of SRY-reliant species can have uncommon XY chromosomal combinations such as XXY and still live. Human sex is determined by the presence or absence of a Y chromosome with a functional SRY gene. Once the SRY gene is activated, cells create testosterone and anti-müllerian hormone which typically ensures the development of a single, male reproductive system. In typical XX embryos, cells secrete estrogen, which drives

pos: XY sex-determination system for maleness. Offspring have two sex chromosomes: an offspring with two X chromosomes will develop female characteristics, and an offspring with an X and a Y chromosome will develop male characteristics. In humans, half of spermatozoons carry X chromosome and the other half Y chromosome. A single gene ("SRY") present on the Y chromosome acts as a signal to set the developmental pathway towards maleness. Presence of this gene starts off the process of virilization. This and other factors result in the sex differences in humans. The cells in females, with two X chromosomes, undergo X-inactivation, in which one of

pos: Y chromosome Y chromosome The Y chromosome is one of two sex chromosomes (allosomes) in mammals, including humans, and many other animals. The other is the X chromosome. Y is the sex-determining chromosome in many species, since it is the presence or absence of Y that determines the male or female sex of offspring produced in sexual reproduction. In mammals, the Y chromosome contains the gene SRY, which triggers testis development. The DNA in the human Y chromosome is composed of about 59 million base pairs. The Y chromosome is passed only from father to son. With a 30% difference between humans

pos: XXXY syndrome XXXY syndrome XXXY syndrome is a genetic disorder characterized by a sex chromosome aneuploidy, where males have two extra X chromosomes. Males typically have only two sex chromosomes, an X and a Y. The presence of one Y chromosome with a functioning SRY gene causes the expression of genes that determine maleness. Because of this, XXXY syndrome only affects males. The additional two X chromosomes in males with XXXY syndrome causes them to have 48 chromosomes, instead of the typical 46. So, XXXY syndrome is often referred to as 48, XXXY. There are a wide variety of symptoms associated with

pos: XXXY syndrome As the syndrome is due to a chromosomal non-disjunction event, the recurrence risk is not high compared to the general population. There has been no evidence found that indicates non-disjunction occurs more often in a particular family. Category Syndromes Category Syndromes XXXY syndrome XXXY syndrome is a genetic disorder characterized by a sex chromosome aneuploidy, where males have two extra X chromosomes. Males typically have only two sex chromosomes, an X and a Y. The presence of one Y chromosome with a functioning SRY gene causes the expression of genes that determine maleness. Because of this, XXXY syndrome only affects

pos: Dominance (genetics) that influence 'maleness', such as the SRY gene for testis determining factor. Dominance rules for sex-linked gene loci are determined by their behavior in the female: because the male has only one allele (except in the case of certain types of Y chromosome aneuploidy), that allele is always expressed regardless of whether it is dominant or recessive. Epistasis [""epi" + "stasis" = to sit on top"] is an interaction between alleles at two "different" gene loci that affect a single trait, which may sometimes resemble a dominance interaction between two "different" alleles at the "same" locus. Epistasis modifies the characteristic

pos: Gender psychology over what gender role they grow into, whether by choosing which parent to imitate, or doing activities such as playing with action figures or dolls. These works added new knowledge to the field of gender psychology. Biological differentiation is fundamental in determining differences in males and females. Males have two different sex chromosomes, an X and a Y. Females have two X chromosomes. The Y chromosome is what determines sexual differentiation. If the Y chromosome is present, growth is along male lines. The SRY is a specific part of the Y chromosome which is the sex-determining gene region of the

pos: Gonad by gonadotropin-releasing hormone produced in the hypothalamus. Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of gonadal ridges, and only later are differentiated to male or female sex organs. The presence of the SRY gene, located on the Y chromosome and encoding the testis determining factor, determines male sexual differentiation. In the absence of the SRY gene from the Y chromosome, the female sex (ovaries instead of testes) will develop. The development of the gonads is a part of the development of the urinary and reproductive organs. Gonad A gonad,

pos: Diphallia apart from having two penises, had normal external genitalia. His two testicles were within normal scrotum and normally positioned. He had two unequal sized glandes at tip of a thick penile shaft, and only urinated through the larger glans. He had a patent anus, one bladder, one normal urethra, normal gastrointestinal and genitourinary systems. (Refer Figure 4.) A male inherits an X chromosome from mother and a Y chromosome from father. The presence of the sex-determining-region of the Y chromosome, or "SRY" gene, determines the embryo being a male. Internal and external male genitalia development from bipotential gonad in embryo.

pos: Testis-determining factor its meiosis, the SRY gene stays on the Y chromosome. If it is transferred to the X chromosome, however, the resulting Y chromosome will not have an SRY gene and can no longer initiate testis development. Offspring which inherit this Y chromosome will have Swyer syndrome, characterized by an XY karyotype and a female phenotype. The X chromosome that results from this crossover event now has a SRY gene, and therefore the ability to initiate testis development. Offspring who inherit this X chromosome will have a condition called XX male syndrome, characterized by an XX karyotype, and a male phenotype.

pos: Male a female. The part of the Y-chromosome which is responsible for maleness is the sex-determining region of the Y-chromosome, the SRY. The SRY activates Sox9, which forms feedforward loops with FGF9 and PGD2 in the gonads, allowing the levels of these genes to stay high enough in order to cause male development; for example, Fgf9 is responsible for development of the spermatic cords and the multiplication of Sertoli cells, both of which are crucial to male sexual development. The ZW sex-determination system, where males have a ZZ (as opposed to ZW) sex chromosome may be found in birds and some

pos: Adam's Curse vitro fertilisation methods. He also introduces the possibility of moving the SRY and associated genes responsible for maleness and male fertility to another chromosome, which he refers to as "the Adonis chromosome", engendering fertile males with an XX karyotype. Adam's Curse Adam's Curse: A Future Without Men (also known as Adam's Curse: A Story of Sex, Genetics, and the Extinction of Men) is a 2003 book by Oxford University human genetics professor Bryan Sykes expounding his hypothesis that with the declining sperm count in men and the continual atrophy of the Y chromosome, within 5,000 generations (approximately 125,000 years) the

pos: David C. Page from the British group that identified the sex-determining gene, which they termed SRY. Despite a belief among geneticists that the Y chromosome contained few genes other than the sex-determining gene, Page continued to map the Y chromosome. He had already published DNA-based deletion maps of the Y chromosome in 1986, and went on to develop comprehensive clone-based physical maps of the chromosome in 1992 and systematic catalogs of Y-linked genes in 1997. Page collaborated with a team at the Genome Institute at Washington University to make a complete map of the Y chromosome, which they achieved in 2003. To do

pos: Sex-determination system into the SRY gene, causing that chromosome to designate sex. After this mutation, the SRY-containing chromosome inverted and was no longer completely homologous with its partner. The regions of the X and Y chromosomes that are still homologous to one another are known as the pseudoautosomal region. Once it inverted, the Y chromosome became unable to remedy deleterious mutations, and thus degenerated. There is some concern that the Y chromosome will shrink further and stop functioning in ten million years: but the Y chromosome has been strictly conserved after its initial rapid gene loss. There are some species, such as

pos: XX male syndrome what point in development these mutations occur. Males typically have one X chromosome and one Y chromosome in each diploid cell of their bodies. Females typically have two X chromosomes. XX males that are SRY-positive have two X chromosomes, with one of them containing genetic material from the Y chromosome, making them phenotypically male but genetically female. The SRY gene plays an important role in sex determination by initiating testicular development. In most XX males the SRY gene is present. The tip of the Y chromosome contains the SRY gene and, during recombination, a translocation occurs in which the SRY

pos: Autosome pair consists of two X chromosomes in females or one X and one Y chromosome in males. Unusual combinations of XYY, XXY, XXX, XXXX, XXXXX or XXYY, among other allosome combinations, are known to occur and usually cause developmental abnormalities. Autosomes still contain sexual determination genes even though they are not sex chromosomes. For example, the SRY gene on the Y chromosome encodes the transcription factor TDF and is vital for male sex determination during development. TDF functions by activating the SOX9 gene on chromosome 17, so mutations of the SOX9 gene can cause humans with an ordinary Y chromosome

pos: XY sex-determination system XXXX, and 49, XXXXX. In most mammals, sex is determined by presence of the Y chromosome. "Female" is the default sex, due to the absence of the Y chromosome. In the 1930s, Alfred Jost determined that the presence of testosterone was required for Wolffian duct development in the male rabbit. SRY is a sex-determining gene on the Y chromosome in the therians (placental mammals and marsupials). Non-human mammals use several genes on the Y chromosome. Not all male-specific genes are located on the Y chromosome. Other species (including most "Drosophila" species) use the presence of two X chromosomes to determine

pos: Sexual differentiation cause anatomic differences, leading to psychological and behavioral differences, some of which are innate and some induced by the social environment. Humans, many mammals, insects and other animals have an XY sex-determination system. Humans have forty-six chromosomes, including two sex chromosomes, XX in females and XY in males. The Y chromosome must carry at least one essential gene which determines testicular formation (originally termed "TDF"). A gene in the sex-determining region of the short arm of the Y, now referred to as "SRY", has been found to direct production of a protein, testis determining factor, which binds to DNA, inducing

pos: Y chromosome shape during mitosis. This shape is vaguely X-shaped for all chromosomes. It is entirely coincidental that the Y chromosome, during mitosis, has two very short branches which can look merged under the microscope and appear as the descender of a Y-shape. Most therian mammals have only one pair of sex chromosomes in each cell. Males have one Y chromosome and one X chromosome, while females have two X chromosomes. In mammals, the Y chromosome contains a gene, SRY, which triggers embryonic development as a male. The Y chromosomes of humans and other mammals also contain other genes needed for normal

pos: Sex chromosome The Y chromosome carries about 78 genes. Most of the Y chromosome genes are involved with essential cell house-keeping activities and sperm production. Only one of the Y chromosome genes, the SRY gene, is responsible for male anatomical traits. When any of the 9 genes involved in sperm production are missing or defective the result is usually very low sperm counts and infertility. Examples of mutations on the X chromosome include more common diseases such as color blindness, hemophilia, and fragile-X syndrome. Other complications include: Sex chromosome An allosome (also referred to as a sex chromosome, heterotypical chromosome, heterochromosome, or

pos: Sex organ development, sex organs originate from a common primordium during early gestation and differentiate into male or female sexes. The SRY gene, usually located on the Y chromosome and encoding the testis determining factor, determines the direction of this differentiation. The absence of it allows the gonads to continue to develop into ovaries. Thereafter, the development of the internal, and external reproductive organs is determined by hormones produced by certain fetal gonads (ovaries or testes) and the cells' response to them. The initial appearance of the fetal genitalia looks basically feminine: a pair of "urogenital folds" with a small protuberance in

pos: Foekje Dillema embryo through nondisjunction. Dillema was probably a 46XX/46XY woman also known as ovotesticular disorder of sex development (DSD) or true hermaphroditism. Her biographer Max Dohle concludes that Dillema, having a Y-chromosome, would never have been allowed to race in the last 45 years. The Barr body test (1966) as well as the test based on PCR (1992) scan for a Y-chromosome or an SRY-gene on the Y-chromosome. All female athletes with a Y-chromosome were expelled from competition from 1966 until 2011. At the end of the century, renowned institutions worldwide protested against the viewpoint of the International Olympic Committee (IOC),

pos: Albert de la Chapelle solve the mystery of maleness without a Y. In the period between 1964 and 1990 he authored 45 peer-reviewed articles on the subject of sex determination. In the end it was detected (i) that the X and Y chromosomes share a tiny pseudoautosomal region that pairs and recombines in meiosis, (ii) that most XX males arise as a consequence of accidental unequal recombination in the paternal meiosis, transferring the male-determining region from the Y to the X). Soon after this had become known the male determining gene SRY was cloned (by others). In 1972 a rare novel recessively inherited lethal

pos: XX male syndrome gene on the Y chromosome is moved to become part of an X chromosome. The presence of the translocated SRY gene leads to an XX embryo developing male characteristics. In rare cases, an XX male does not have the SRY gene. The exact cause of this condition is unknown but it has been proposed that mutations in the SOX9 gene may contribute to this syndrome since SOX9 plays a role in testes differentiation during development. Another proposed cause is mutations to the DAX1 gene which encodes a nuclear hormone receptor. DAX1 represses masculinizing genes, therefore, if there is a loss

pos: Prenatal development nucleus of the ovum and the second set from the nucleus of the sperm. The zygote is male if the egg is fertilized by a sperm that carries a Y chromosome, and it is female if the egg is fertilized by a sperm that carries an X chromosome. The Y chromosome contains a gene, SRY, which will switch on androgen production at a later stage, leading to the development of a male body type. In contrast, the mitochondrial genetic information of the zygote comes entirely from the mother via the ovum. The embryonic period in humans begins at fertilization (penetration

pos: Sexual differentiation in humans triggering male development. The "default sex," in the absence of a Y chromosome, is female-like. This is because of the presence of the sex-determining region of the Y chromosome, also known as the SRY gene. Thus, male mammals typically have an X and a Y chromosome (XY), while female mammals typically have two X chromosomes (XX). In humans, biological sex is determined by five factors present at birth: the presence or absence of a Y chromosome, the type of gonads, the sex hormones, the internal genitalia (such as the uterus in females), and the external genitalia. Chromosomal sex is determined

pos: M33 (gene) "Drosophila" mediate changes in higher-order chromatin structure to maintain the repressed state of developmentally regulated genes . M33 deficiency interferes with steps upstream of the Y-chromosome-specific SRY gene may cause sex reversal. It may also involved in the campomelic syndrome and neoplastic disorders linked to allele loss in this region. Disruption of the murine M33 gene, displayed posterior transformation of the sternal ribs and vertebral columns . The mouse M33 gene is located on the Chromosome 11, from base pair 119,022,962 to base pair 119,031,270 (Build GRCm38/mm10)(Map)"." Human homolog of "M33", Chromobox homolog 2 ("CBX2" ) is located on Chromosome

pos: Testis-determining factor using techniques such as microarray screening of the genital ridge genes at varying developmental stages, mutagenesis screens in mice for sex-reversal phenotypes, and identifying the genes that transcription factors act on using chromatin immunoprecipitation. Testis-determining factor Testis-determining factor (TDF), also known as sex-determining region Y (SRY) protein, is a DNA-binding protein (also known as gene-regulatory protein/transcription factor) encoded by the SRY gene that is responsible for the initiation of male sex determination in humans. SRY is an intronless sex-determining gene on the Y chromosome in therians (placental mammals and marsupials); mutations in this gene lead to a range of disorders

pos: XXYY syndrome XXYY syndrome XXYY syndrome is a sex chromosome anomaly in which males have an extra X and Y chromosome. Human cells usually contain two sex chromosomes, one from the mother and one from the father. Usually, females have two X chromosomes (XX) and males have one X and one Y chromosome (XY). The appearance of at least one Y chromosome with a properly functioning SRY gene makes a male. Therefore, humans with XXYY are genotypically male. Males with XXYY syndrome have 48 chromosomes instead of the typical 46. This is why XXYY syndrome is sometimes written as 48,XXYY syndrome or

pos: XX male syndrome XX male syndrome XX male syndrome is a rare congenital condition where an individual with a female genotype has phenotypically male characteristics that can vary between cases. In 90% of these individuals the syndrome is caused by unequal crossing over between X and Y chromosomes during meiosis in the father, and results in the X chromosome containing the SRY gene, as opposed to the Y chromosome where it is normally found. When the X with the SRY gene combines with a normal X from the mother during fertilization, the result is an XX male. Less common are SRY-negative XX males

pos: Testis-determining factor Testis-determining factor Testis-determining factor (TDF), also known as sex-determining region Y (SRY) protein, is a DNA-binding protein (also known as gene-regulatory protein/transcription factor) encoded by the SRY gene that is responsible for the initiation of male sex determination in humans. SRY is an intronless sex-determining gene on the Y chromosome in therians (placental mammals and marsupials); mutations in this gene lead to a range of disorders of sex development (DSD) with varying effects on an individual's phenotype and genotype. TDF is a member of the SOX (SRY-like box) gene family of DNA-binding proteins. When complexed with the SF1 protein, TDF

neg: XY sex-determination system patients with Turner's syndrome, who grew up as phenotypic females, and found them to be X0 (hemizygous for X and no Y). At the same time, Jacob & Strong described a case of a patient with Klinefelter syndrome (XXY), which implicated the presence of a Y chromosome in development of maleness. All these observations lead to a consensus that a dominant gene that determines testis development (TDF) must exist on the human Y chromosome. The search for this testis-determining factor (TDF) led a team of scientists in 1990 to discover a region of the Y chromosome that is necessary for

neg: Human genetics Y chromosome. Since Y chromosomes can only be found in males, Y linked traits are only passed on from father to son. The testis determining factor, which is located on the Y chromosome, determines the maleness of individuals. Besides the maleness inherited in the Y-chromosome there are no other found Y-linked characteristics. A pedigree is a diagram showing the ancestral relationships and transmission of genetic traits over several generations in a family. Square symbols are almost always used to represent males, whilst circles are used for females. Pedigrees are used to help detect many different genetic diseases. A pedigree can

neg: XY sex-determination system so far investigated definitely have the XY system of sex determination. A temperature-dependent sex determination system is found in some reptiles. All animals have a set of DNA coding for genes present on chromosomes. In humans, most mammals, and some other species, two of the chromosomes, called the X chromosome and Y chromosome, code for sex. In these species, one or more genes are present on their Y chromosome that determine maleness. In this process, an X chromosome and a Y chromosome act to determine the sex of offspring, often due to genes located on the Y chromosome that code

neg: Male reproductive system This occurs when one X chromosome contains a segment of the Y chromosome, which was inserted into the X chromosome of the father's sperm. Rarely females are born with the XY genotype. They are found to be missing the same portion of the Y chromosome it was inserted into the chromosome of XX males. The gene for sexual differentiation in humans, called the testis determining factor (TDF), is located on the short arm of the Y chromosome. The presence or absence of the Y chromosome determines whether the embryo will have testes or ovaries. An abnormal number of sex chromosomes

neg: Rosy-faced lovebird colour genetics little bit more complex because these recessive traits are carried on the genetic information which determines the gender of a bird. These genes are usually referred to in simplified terms as X and Y genes. In mammals, it is the male that determines the sex of their offspring, in that mammal males have one X gene and one Y gene on a chromosome pairing (XY) and can pass either to an offspring - while a mammal female can only pass an X, due to their chromosomal pairing of XX. However, in birds and reptiles, this pairing is just the opposite:

neg: Sex determination in Silene during pairing in male meiosis (XY). When recombination does occur in XY chromosomes, it is confined to the tips of the chromosome, leaving most of the genetic material in the Y chromosome intact. Several studies concentrated on "Silene latifolia" have shown a correlation between loci on the Y chromosome and the sex that is expressed phenotypically in the flower"." Two of these sex-linked genes “promote maleness” (male fertility and male promotion) and one of them codes for female suppression. Therefore, the Y chromosome carries three dominant genes that determine the sexual expression in a "Silene" offspring. If there are deletions

neg: Y chromosome the Y chromosome was the pair of the X chromosome discovered in 1890 by Hermann Henking. She realized that the previous idea of Clarence Erwin McClung, that the X chromosome determines sex, was wrong and that sex determination is, in fact, due to the presence or absence of the Y chromosome. Stevens named the chromosome "Y" simply to follow on from Henking's "X" alphabetically. The idea that the Y chromosome was named after its similarity in appearance to the letter "Y" is mistaken. All chromosomes normally appear as an amorphous blob under the microscope and only take on a well-defined

neg: XY sex-determination system femaleness. One X chromosome gives putative maleness. The presence of Y chromosome genes is required for normal male development. Birds and many insects have a similar system of sex determination ("ZW sex-determination system"), in which it is the females that are heterogametic (ZW), while males are homogametic (ZZ). Many insects of the order Hymenoptera instead have a system (the "haplo-diploid sex-determination system"), where the males are haploid individuals (which have just one chromosome of each type), while the females are diploid (with chromosomes appearing in pairs). Some other insects have the "X0 sex-determination system", where just one chromosome type appears

neg: RBMX RBMX Heterogeneous nuclear ribonucleoprotein G is a protein that in humans is encoded by the "RBMX" gene. This gene belongs to the RBMY gene family which includes candidate Y chromosome spermatogenesis genes. This gene, an active X chromosome homolog of the Y chromosome RBMY gene, is widely expressed whereas the RBMY gene evolved a male-specific function in spermatogenesis. Pseudogenes of this gene, found on chromosomes 1, 4, 9, 11, and 6, were likely derived by retrotransposition from the original gene. Alternatively spliced transcript variants encoding different isoforms have been identified but their biological nature has not been determined. RBMX has

neg: Y chromosome trace direct paternal ancestral lines. The following are some of the gene count estimates of human Y chromosome. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). Among various projects, the collaborative consensus coding sequence project (CCDS) takes an extremely conservative strategy. So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes. In general, the human Y chromosome is extremely gene poor—it is one of the largest gene deserts in the human genome. Disregarding pseudoautosomal genes, genes

neg: X-linked recessive inheritance X-linked recessive inheritance X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males (who are necessarily hemizygous for the gene mutation because they have one X and one Y chromosome) and in females who are homozygous for the gene mutation, see zygosity. X-linked inheritance means that the gene causing the trait or the disorder is located on the X chromosome. Females have two X chromosomes, while males have one X and one Y chromosome. Carrier females who have only one copy of the

neg: Nettie Stevens that existed in small-large pairs (now known as XY chromosome pairs) and she also saw chromosomes that were unpaired, XO. Hermann Henking had studied firebug chromosomes earlier and noticed the chromosome now called X, but didn't find the small chromosome now called Y. Stevens realized that the previous idea of Clarence Erwin McClung, that the X chromosome determines sex, was wrong and that sex determination is, in fact, due to the presence or absence of the small (Y) chromosome. Stevens did not name the chromosomes X or Y. Their current names came later. Edmund Wilson worked on spermatogenesis preparations simultaneously

neg: DAZ associated protein 1 DAZ associated protein 1 DAZ-associated protein 1 is a protein that in humans is encoded by the "DAZAP1" gene. In mammals, the Y chromosome directs the development of the testes and plays an important role in spermatogenesis. A high percentage of infertile men have deletions that map to regions of the Y chromosome. The DAZ1 (Deleted in Azoospermia) gene cluster maps to the AZFc region of the Y chromosome and is deleted in many azoospermic and severely oligospermic men. It is thought that the DAZ gene cluster arose from the transposition, amplification, and pruning of the ancestral autosomal gene DAZL

neg: Y chromosome that human Y chromosome is able to "recombine" with itself, using palindrome base pair sequences. Such a "recombination" is called gene conversion. In the case of the Y chromosomes, the palindromes are not noncoding DNA; these strings of bases contain functioning genes important for male fertility. Most of the sequence pairs are greater than 99.97% identical. The extensive use of gene conversion may play a role in the ability of the Y chromosome to edit out genetic mistakes and maintain the integrity of the relatively few genes it carries. In other words, since the Y chromosome is single, it has

neg: Sex determination in Silene and mutations in the Y chromosome during reproduction, then different sex-linked genes are lost. The different combinations of possible sex-related genes that an individual "Silene" can have in one Y chromosome are what creates the rich variation of sexual phenotypes throughout this genus. The system for determining sex in "Silene latifolia" is close to that found in humans because in both cases the Y chromosome determines what reproductive mechanisms will be expressed in the offspring. They differ because there are multiple sex determining genes on the Y chromosome of "S. latifolia", while in humans the presence or absence of the

neg: DAZAP2 DAZAP2 DAZ-associated protein 2 is a protein that in humans is encoded by the "DAZAP2" gene. In mammals, the Y chromosome directs the development of the testes and plays an important role in spermatogenesis. A high percentage of infertile men have deletions that map to regions of the Y chromosome. The DAZ (deleted in azoospermia) gene cluster maps to the AZFc region and is deleted in many azoospermic and severely oligospermic men. It is thought that the Y chromosomal DAZ gene cluster arose from the transposition, amplification, and pruning of the ancestral autosomal gene DAZL. This gene encodes a RNA-binding

neg: RBMX been shown to interact with SFRS10 and CDC5L. Model organisms have been used in the study of RBMX function. A conditional knockout mouse line called "Rbmx" was generated at the Wellcome Trust Sanger Institute. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Additional screens performed: - In-depth immunological phenotyping RBMX Heterogeneous nuclear ribonucleoprotein G is a protein that in humans is encoded by the "RBMX" gene. This gene belongs to the RBMY gene family which includes candidate Y chromosome spermatogenesis genes. This gene, an active X chromosome homolog of the Y chromosome RBMY

neg: PCDHY PCDHY PCDH11Y is a gene unique to human males that encodes Protocadherin 11Y, a protein that guides the development of nerve cells. PCDH11X, located on the X chromosome, is common, in both sexes, to humans and our nearest relative, the chimpanzee; however, PCDH11Y, located on the Y chromosome, is unique to males. In terms of human evolution, it has been estimated that pcdh11x "gene jumped" from X to Y around three million years ago; coincident with increased human brain size and the first use of tools. Furthermore, around 120,000 to 200,000 years ago, the PCDH11Y gene was able to further

neg: Minor histocompatibility antigen encoded by a gene on Y chromosome. The peptide was foreign to the female T cells and females lack the Y chromosome and, thus, this MiHA. The MiHAs encoded by the Y chromosome are known as HY antigens. H-Y antigens are encoded by genes on the Y chromosome. Both HLA class I and II alleles have been found to present these antigens. Some of these antigens are ubiquitiouly expressed in nucleated male cells, and the presence of these antigens has been associated with a greater risk of developing GVHD allogeneic stem cell transplantation for a HLA matched gene when there's

neg: Sex determination in Silene Y chromosome strictly determines whether the offspring is male or female. Different combinations of the genes present in a "Silene" Y chromosome affect the sexual expression in the organism"." For example, there are two genetic variations that can lead to male sterility in "S. latifolia": if it possesses two Y chromosomes (YY) or if the Y chromosome possesses the female suppression and male promoting genes. "Silene" are also susceptible to a type of sexually transmitted infection that causes sterility. Another possible combination includes the presence of all three sex-linked genes (male suppressing, female suppressing, and male promoting) which produce virile

neg: H-Y antigen histocompatibility antigen, seemed to be encoded in the SMCY gene (acronym for 'selected mouse cDNA on Y'), later identified as an 11-residue peptide from the Lysine-Specific Demethylase 5D protein (KDM5D gene) presented by HLA-B7. A third example is MEA1. It has been shown that male mice lacking in the H-Y antigen, hence lacking in the gene producing it, have also lost genetic information responsible for spermatogenesis. This result also identified a gene on the mouse Y chromosome, distinct from the testis-determining gene, that was essential for spermatogenesis, thus raising the possibility that the very product of this "spermatogenesis gene" is

neg: Offspring consists of taking genes from the male chromosomes and genes from the female chromosome, resulting in a process of meiosis occurring, and leading to the splitting of the chromosomes evenly. Depending on which genes are dominantly expressed in the gene will result in the sex of the offspring. The female will always give an X chromosome, whereas the male, depending on the situation, will either give an X chromosome or a Y chromosome. If a male offspring is produced, the gene will consist of an X and a Y chromosome. If two X chromosomes are expressed and produced, it produces

neg: Sex chromosome X chromosome in each body cell. All diploid organisms with allosome-determined sex get half of their allosomes from each of their parents. In mammals, females are XX, they can pass along either of their X’s, and since the males are XY they can pass along either an X or a Y. For a mammal to be chromosomally female, the individual must receive an X chromosome from both parents, whereas to be chromosomally male, the individual must receive a X chromosome from their mother and a Y chromosome from their father. It is thus the male’s sperm that determines the sex

neg: Y chromosome application of genetics to traditional genealogy), use of the information contained in the Y chromosome is of particular interest because, unlike other chromosomes, the Y chromosome is passed exclusively from father to son, on the patrilineal line. Mitochondrial DNA, maternally inherited to both sons and daughters, is used in an analogous way to trace the matrilineal line. Research is currently investigating whether male-pattern neural development is a direct consequence of Y-chromosome-related gene expression or an indirect result of Y-chromosome-related androgenic hormone production. The presence of male chromosomes in fetal cells in the blood circulation of women was discovered in 1974.

neg: TRAPPC2 protein can bind MBP1 and block its transcriptional repression capability. The TRAPPC2 gene is located on the X-chromosome at position 22 between base-pairs 13,712,241 to 13,734,634. Mutations in this gene are a cause of X-linked spondyloepiphyseal dysplasia tarda (SEDT). TRAPPC2 has been shown to interact with Alpha-enolase and CLIC1. TRAPPC2 Trafficking protein particle complex subunit 2 (TRAPPC2) also known as MBP-1-interacting protein 2A (MIP-2A) is a protein that in humans is encoded by the "TRAPPC2" gene. A processed pseudogene of this gene is located on chromosome 19, and other pseuodogenes of it are found on chromosome 8 and the Y

neg: Genetics two of each chromosome and thus two copies of every gene. The two alleles for a gene are located on identical loci of the two homologous chromosomes, each allele inherited from a different parent. Many species have so-called sex chromosomes that determine the gender of each organism. In humans and many other animals, the Y chromosome contains the gene that triggers the development of the specifically male characteristics. In evolution, this chromosome has lost most of its content and also most of its genes, while the X chromosome is similar to the other chromosomes and contains many genes. The X

neg: Short stature homeobox gene other symptoms), Léri-Weill dyschondrosteosis, and Langer mesomelic dysplasia. Gene dosage effects of extra copies of SHOX may be a cause of the increased stature seen in other sex chromosome aneuploidy conditions such as 47,XXX, 47,XYY, 47,XXY, 48,XXYY, etc. The SHOX gene is composed of 6 different exons and is located in the pseudoautosomal region (PAR1) of the X chromosome (Xp22.33) and Y chromosome. Similar genes are present in a variety of animals and insects. The SHOX gene is a homeobox gene, meaning that it helps regulate development. Short stature homeobox gene The short stature homeobox (SHOX) gene is a gene,

neg: Segmental Duplication on the Human Y Chromosome CCL3L1 due to duplication is associated with decreased susceptibility to the HIV infection. The human Y chromosome contains the greatest proportion of duplicated sequence within the human genome at 50.4%. The majority of the chromosome (41Mb out of 63Mb) is made up of three blocks of highly reiterated satellites and other repeats. The other 22Mb euchromatin region also has a unique genetic structure with large gene-rich palindromes. On the human Y chromosome as well as other primate Y chromosomes, the pericentromeric and subtelomeric regions are the most important. The pericentromeric region is the area around the centromere of the chromosome.

neg: Sex verification in sports of doctors". For a period of time these tests were mandatory for female athletes, due to fears that male athletes would pose as female athletes and have an unfair advantage over their competitors. Chromosome testing was introduced by the International Olympic Committee during the 1968 Summer Olympics. This tested for the Y-chromosome, and was designed to identify males potentially disguised as females. This method of testing was later abolished, as it was shown to be inconclusive in identifying maleness. The International Association of Athletics Federations ceased sex screening for all athletes in 1992, but retained the option of assessing the

neg: C8orf46 with breast cancer in humans. The gene has been researched in connection with estrogen receptor 1- enhancer (ESR1), whose expression determines if a breast cancer patient receives endocrine therapy. It is predicted that C8orf46 has ESR1 enhancer regions that become hypermethylated and promote acquired endocrine resistance in breast cancer. C8orf46 Chromosome 8 open reading frame 46 (C8orf46) is a protein coding gene, which in humans is located along the forward strand of chromosome 8. The gene is approximately 58,522 base pairs long, and encodes for 207 amino acids. C8orf46 is found to be highly expressed in regions of the brain

neg: Chadong language reported that most of the patrilineal and matrilineal gene pools of Chadong are characteristic lineages of southern China. Some ancient Southeast Asian lineages (Y chromosome haplogroups C and D, mtDNA haplogroups M*, M33, M74, and R*) were also identified in Chadong. Chadong shows patterns of the Y chromosome and mtDNA diversities similar to other southern populations, especially Kam-Sui populations, which was actually in accordance with linguistic classification. However, the origin of Chadong seems to be much more complex. Recent gene flow from Sino-Tibetan populations is detected in the patrilineal side of Chadong, such as Y chromosome haplogroups O3a1c-002611, O3a2c1*-M134, and

neg: Y chromosome the lineage leading to humans. Without the ability to recombine during meiosis, the Y chromosome is unable to expose individual alleles to natural selection. Deleterious alleles are allowed to "hitchhike" with beneficial neighbors, thus propagating maladapted alleles in to the next generation. Conversely, advantageous alleles may be selected against if they are surrounded by harmful alleles (background selection). Due to this inability to sort through its gene content, the Y chromosome is particularly prone to the accumulation of "junk" DNA. Massive accumulations of retrotransposable elements are scattered throughout the Y. The random insertion of DNA segments often disrupts encoded gene

neg: Y chromosome recombine with the X chromosome are referred to as the pseudoautosomal region. The rest of the Y chromosome is passed on to the next generation intact, allowing for its use in tracking human evolution. By one estimate, the human Y chromosome has lost 1,393 of its 1,438 original genes over the course of its existence, and linear extrapolation of this 1,393-gene loss over 300 million years gives a rate of genetic loss of 4.6 genes per million years. Continued loss of genes at the rate of 4.6 genes per million years would result in a Y chromosome with no functional

neg: Rett syndrome female born with an MECP2 mutation on her X chromosome has another X chromosome with an ostensibly normal copy of the same gene, while a male with the mutation on his X chromosome has no other X chromosome, only a Y chromosome; thus, he has no normal gene. Without a normal gene to provide normal proteins in addition to the abnormal proteins caused by a MECP2 mutation, the XY karyotype male fetus is unable to slow the development of the disease, hence the failure of many male fetuses with a MECP2 mutation to survive to term. Females with a MECP2

neg: TRAPPC2 TRAPPC2 Trafficking protein particle complex subunit 2 (TRAPPC2) also known as MBP-1-interacting protein 2A (MIP-2A) is a protein that in humans is encoded by the "TRAPPC2" gene. A processed pseudogene of this gene is located on chromosome 19, and other pseuodogenes of it are found on chromosome 8 and the Y chromosome. Two transcript variants encoding the same protein have been found for this gene. Trafficking protein particle complex subunit 2 is thought to be part of a large multisubunit complex involved in the targeting and fusion of endoplasmic reticulum-to-Golgi transport vesicles with their acceptor compartment. In addition, the encoded

neg: Y chromosome duplicates of its genes on itself instead of having a second, homologous, chromosome. When errors occur, it can use other parts of itself as a template to correct them. Findings were confirmed by comparing similar regions of the Y chromosome in humans to the Y chromosomes of chimpanzees, bonobos and gorillas. The comparison demonstrated that the same phenomenon of gene conversion appeared to be at work more than 5 million years ago, when humans and the non-human primates diverged from each other. In the terminal stages of the degeneration of the Y chromosome, other chromosomes increasingly take over genes and

neg: Y chromosome microdeletion Y chromosome microdeletion Y chromosome microdeletion "(YCM)" is a family of genetic disorders caused by missing gene(s) in the Y chromosome. Many men with YCM exhibit no symptoms and lead normal lives. However, YCM is also known to be present in a significant number of men with reduced fertility. Men with reduced sperm production (in up to 20% of men with reduced sperm count, some form of YCM has been detected) varies from oligozoospermia, significant lack of sperm, or azoospermia, complete lack of sperm. The mechanism of mutation is not different for Y-chromosome microdeletion. However, the ability to repair it

neg: Drosophila melanogaster and divide during the larval stages—unlike most other cells of the larva, which have differentiated to perform specialized functions and grow without further cell division. At metamorphosis, the larva forms a pupa, inside which the larval tissues are reabsorbed and the imaginal tissues undergo extensive morphogenetic movements to form adult structures. "Drosophila" flies have both X and Y chromosomes, as well as autosomes. Unlike humans, the Y chromosome does not confer maleness; rather, it encodes genes necessary for making sperm. Sex is instead determined by the ratio of X chromosomes to autosomes. Furthermore, each cell "decides" whether to be male

neg: Segmental Duplication on the Human Y Chromosome Y chromosome in marsupial and placental mammals. On this Y chromosome, ampliconic genes are present in multiple copies. This group of genes undergo gene conversion. The ampliconic genes evolve faster than their autosomal counterparts. In fact, they even evolve faster than single-copy genes located on the Y chromosome. Finally, these ampliconic genes evolve faster in modern human and chimpanzees as compared to the Old World monkeys of the past. The male-specific region of the Y chromosome contains a mosaic of heterochromatic sequences. In addition, it also made up of three classes of euchromatic sequence, which are the ampliconic genes, X-transposed,

neg: Haemophilia bone destruction. Females possess two X-chromosomes, males have one X and one Y-chromosome. Since the mutations causing the disease are X-linked recessive, a female carrying the defect on one of her X-chromosomes may not be affected by it, as the equivalent allele on her other chromosome should express itself to produce the necessary clotting factors, due to X inactivation. However, the Y-chromosome in the male has no gene for factors VIII or IX. If the genes responsible for production of factor VIII or factor IX present on a male's X-chromosome are deficient there is no equivalent on the Y-chromosome to

neg: Y chromosome microdeletion Western Pacific region. Additional genes associated with spermatogenesis in men and reduced fertility upon Y chromosome deletions include RBM, DAZ, SPGY, and TSPY. Y chromosome microdeletion Y chromosome microdeletion "(YCM)" is a family of genetic disorders caused by missing gene(s) in the Y chromosome. Many men with YCM exhibit no symptoms and lead normal lives. However, YCM is also known to be present in a significant number of men with reduced fertility. Men with reduced sperm production (in up to 20% of men with reduced sperm count, some form of YCM has been detected) varies from oligozoospermia, significant lack of

neg: 40S ribosomal protein S4, Y isoform 2 40S ribosomal protein S4, Y isoform 2 Ribosomal protein S4, Y-linked 2 also known as RPS4Y2 is a protein which in humans is encoded by the "RPS4Y2" gene which resides on the Y chromosome. Cytoplasmic ribosomes, organelles that catalyze protein synthesis, consist of a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and approximately 80 structurally distinct proteins. This gene encodes ribosomal protein S4, a component of the 40S subunit. Ribosomal protein S4 is the only ribosomal protein known to be encoded by more than one gene, namely this gene, RPS4Y1

neg: Y chromosome since the divergence of humans and chimpanzees between 6–7 million years ago, and a scientific report in 2012 stated that only one gene had been lost since humans diverged from the rhesus macaque 25 million years ago. These facts provide direct evidence that the linear extrapolation model is flawed and suggest that the current human Y chromosome is either no longer shrinking or is shrinking at a much slower rate than the 4.6 genes per million years estimated by the linear extrapolation model. The human Y chromosome is particularly exposed to high mutation rates due to the environment in which

neg: Multiregional origin of modern humans model. However, the mitochondrial and Y chromosome data could not be explained by the same modern human expansion out of Africa; the Y chromosome expansion would have involved genetic mixing that retained regionally local mitochondrial lines. In addition, the Y chromosome data indicated a later expansion back into Africa from Asia, demonstrating that gene flow between regions was not unidirectional. An early analysis of 15 noncoding sites on the X chromosome found additional inconsistencies with the recent African replacement hypothesis. The analysis found a multimodal distribution of coalescence times to the most recent common ancestor for those sites, contrary to

neg: Amelogenin development. The latest research indicates that these proteins regulate the initiation and growth of hydroxyapatite crystals during the mineralization of enamel. In addition, amelogenins appear to aid in the development of cementum by directing cementoblasts to the tooth's root surface. The amelogenin gene has been most widely studied in humans, where it is a single copy gene, located on the X and Y chromosomes at Xp22.1-Xp22.3 and Yp 11.2 [5]. The amelogenin gene’s location on sex chromosomes has implications for variability both between the X chromosome form (AMELX) and the Y chromosome form (AMELY), and between alleles of AMELY among

neg: SHOX2 and it is implicated in the short stature phenotype of Turner syndrome patients. This gene is considered to be a candidate gene for Cornelia de Lange Syndrome. SHOX2 localises on chromosome 3, so it is an autosomal and not a pseudoautosomal homeobox (SHOX, which localises on the PAR1 region of chromosome X and Y, has a pseudoautosomal hereditability). SHOX2 Short stature homeobox 2, also known as homeobox protein Og12X or paired-related homeobox protein SHOT, is a protein that in humans is encoded by the "SHOX2" gene. SHOX2 is a member of the homeobox family of genes that encode proteins containing

neg: David C. Page body, Page further concluded that these genes give rise to differences in the biochemistry of male and female tissues. In super-resolution studies of the sex chromosomes, Page has found evidence of an evolutionary "arms race" between the X and Y chromosomes for transmission to the next generation. In one study, Page found that human X and mouse Y chromosomes have converged, independently acquiring and amplifying gene families expressed in testicular germ cells. Another study found that the mouse Y chromosome had acquired and massively amplified genes homologous to the testis-expressed gene families on the mouse X chromosome. Page used the

neg: DAZAP2 protein with two RNP motifs that was originally identified by its interaction with the infertility factors DAZ and DAZL. DAZAP2 has been shown to interact with DAZ1. DAZAP2 DAZ-associated protein 2 is a protein that in humans is encoded by the "DAZAP2" gene. In mammals, the Y chromosome directs the development of the testes and plays an important role in spermatogenesis. A high percentage of infertile men have deletions that map to regions of the Y chromosome. The DAZ (deleted in azoospermia) gene cluster maps to the AZFc region and is deleted in many azoospermic and severely oligospermic men. It

neg: Y-STR zygote making process. Y-STRs are assigned names by the HUGO gene nomenclature committee. Some testing companies have different formats for the way STR markers are written. For example, the marker DYS455 may be written as DYS455, DYS 455, DYS#455, or DYS# 455. The scientific standard accepted by HUGO and NIST is DYS455. DYS is a variation on the jargon used in human autosomal STR testing where the second character is typically reserved for the chromosome number (e.g. D8S1179). D = DNA Y = Y-chromosome S = (unique) segment There are regions on DNA that are made up of multiple copies

neg: Y chromosome a well adapted Y chromosome free of excessive mutation, it may never make it in to the next gene pool. The repeat random loss of well-adapted Y chromosomes, coupled with the tendency of the Y chromosome to evolve to have more deleterious mutations rather than less for reasons described above, contributes to the species-wide degeneration of Y chromosomes through Muller's ratchet. As it has been already mentioned, the Y chromosome is unable to recombine during meiosis like the other human chromosomes; however, in 2003, researchers from MIT discovered a process which may slow down the process of degradation. They found

neg: PRKX PRKX Protein kinase, X-linked is a protein that in humans is encoded by the PRKX gene. This gene encodes a serine threonine protein kinase that has similarity to the catalytic subunit of cyclic AMP dependent protein kinases. The encoded protein is developmentally regulated and may be involved in renal epithelial morphogenesis. This protein may also be involved in macrophage and granulocyte maturation. Abnormal recombination between this gene and a related pseudogene on chromosome Y is a frequent cause of sex reversal disorder in XX males and XY females. Pseudogenes of this gene are found on chromosomes X, 15 and Y.

neg: Mulao people the patrilineal and matrilineal gene pools of Mulao are characteristic lineages of southern China. Some ancient Southeast Asian lineages (Y chromosome haplogroups C and D, mtDNA haplogroups M*, M33, M74, and R*) were also identified in Mulao. Mulao shows patterns of the Y chromosome and mtDNA diversities similar to other southern populations, especially Kam-Sui populations, which was actually in accordance with linguistic classification. However, the origin of Mulao seems to be much more complex. Recent gene flow from Sino-Tibetan populations is detected in the patrilineal side of Mulao, such as Y chromosome haplogroups O3a1c-002611, O3a2c1*-M134, and O3a2c1a-M117, probably through the

neg: Female reproductive system that open into the abdominal cavity. In the absence of fertilization, the ovum will eventually traverse the entire reproductive tract from the fallopian tube until exiting the vagina through menstruation. The reproductive tract can be used for various transluminal procedures such as fertiloscopy, intrauterine insemination, and transluminal sterilization. Chromosome characteristics determine the genetic sex of a fetus at conception. This is specifically based on the 23rd pair of chromosomes that is inherited. Since the mother's egg contains an X chromosome and the father's sperm contains either an X or Y chromosome, it is the male who determines the fetus's sex.

neg: PSMA6 PSMA6 Proteasome subunit alpha type-6 is a protein that in humans is encoded by the "PSMA6" gene. This protein is one of the 17 essential subunits (alpha subunits 1-7, constitutive beta subunits 1-7, and inducible subunits including beta1i, beta2i, beta5i) that contributes to the complete assembly of 20S proteasome complex. The gene "PMSA6" encodes a member of the peptidase T1A family, that is a 20S core alpha subunit. A pseudogene has been identified on the Y chromosome. The gene has 8 exons and locates at chromosome band 14q13. The human protein proteasome subunit alpha type-6 is also known as 20S

neg: DAX1 and hypogonadotropic hypogonadism, which are the main characteristics of this disorder. Duplication of genetic material on the X chromosome in the region that contains the NR0B1 gene can cause a condition called dosage-sensitive sex reversal. The extra copy of the NR0B1 gene prevents the formation of male reproductive tissues. People who have this duplication usually appear to be female, but are genetically male with both an X and a Y chromosome. In some cases, genetic material is deleted from the X chromosome in a region that contains several genes, including NR0B1. This deletion results in a condition called adrenal hypoplasia

neg: Sex chromosome and female traits, but also those for some other characteristics as well. Genes that are carried by either sex chromosome are said to be sex linked. Sex linked diseases are passed down through families through one of the X or Y chromosomes. Since only men inherit Y chromosomes, they are the only ones to inherit Y-linked traits. Men and women can get the X-linked ones since both inherit X chromosomes. An allele is either said to be dominant or recessive. Dominant inheritance occurs when an abnormal gene from one parent causes disease even though the matching gene from the other

neg: Hunter syndrome from their mother and one Y chromosome that they inherit from their father. If a female inherits one copy of the mutant allele for MPS II, she will usually have a normal copy of the "IDS" gene which can compensate for the mutant allele. This is known as being a genetic carrier. However, a male who inherits a defective X chromosome does not have another X chromosome to compensate for the mutant gene. Thus, a female would need to inherit two mutant genes in order to develop Hunter Syndrome, while a male patient only needs to inherit one mutant gene.

neg: DAZ1 DAZ1 Deleted in azoospermia 1, also known as DAZ1, is a protein which in humans is encoded by the "DAZ1" gene. This gene is a member of the DAZ gene family and is a candidate for the human Y-chromosomal azoospermia factor (AZF). Its expression is restricted to pre-meiotic germ cells, particularly in spermatogonia. It encodes an RNA-binding protein that is important for spermatogenesis. Four copies of this gene are found on chromosome Y within palindromic duplications; one pair of genes is part of the P2 palindrome and the second pair is part of the P1 palindrome. Each gene contains a

neg: Drosophila hybrid sterility "Drosophila paulistorum" there is information suggesting that if Y chromosome and cytoplasm are from different parents, the male is usually sterile. (Perez-Salas & Ehrman 1971) X-Y interactions are the most likely cause of sterility in male hybrids. It has been shown that interbreeding organisms that have more genetic compatibilities have less disruption of spermatogenesis and normal sized testes, while species who are less genetically compatible have a higher disruption in spermatogenesis and generally have atrophied testes. (Reference needed) Another possible cause of sterility among species in which presence or absence of one or the other sex chromosome determines gender, is

neg: Haemophilia in European royalty also inherited a second X chromosome from the other parent that is likely to carry a non-mutated copy of the gene, capable of directing appropriate clotting. Such a female, with normal clotting but possessing a single mutated copy of the gene, is called a carrier. Males only possess a single X chromosome, inherited from their mother, having received a Y chromosome from their father instead of a second X. If their sole X chromosome contains the haemophilia mutation they possess no second copy to provide for normal function, as in carrier females. Each child of a carrier will have a

neg: X-linked recessive inheritance to express the trait. The most common X-linked recessive disorders are: Theoretically, a mutation in any of the may cause disease, but below are some notable ones, with short description of symptoms: [Female X-linked disorders] X-linked recessive inheritance X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males (who are necessarily hemizygous for the gene mutation because they have one X and one Y chromosome) and in females who are homozygous for the gene mutation, see zygosity. X-linked inheritance means that the gene

neg: Short stature homeobox gene Short stature homeobox gene The short stature homeobox (SHOX) gene is a gene, located on both the X and Y chromosomes, which is associated with short stature in humans if mutated or present in only one copy (haploinsufficiency). The gene was first found during a search for the cause of short stature in women with Turner syndrome, in which there is loss of genetic material from the X chromosome, classically by loss of one entire X chromosome. Since its discovery, the SHOX gene has been found to play a role in idiopathic short stature (short stature of unknown cause without

neg: Tsix Tsix Tsix is a non-coding RNA gene that is antisense to the Xist RNA. Tsix binds Xist during X chromosome inactivation. The name Tsix comes from the reverse of Xist, which stands for X-inactive specific transcript. Female mammals have two X chromosomes and males have one X and one Y chromosome. The X chromosome has many active genes. This leads to dosage compensation problems: the two X chromosomes in the female will create twice as many gene products as the one X in the male. To mitigate this, one of the X chromosomes is inactivated in females, so that each

neg: DAZ1 DAZL and DAZ associated protein 1. DAZ1 Deleted in azoospermia 1, also known as DAZ1, is a protein which in humans is encoded by the "DAZ1" gene. This gene is a member of the DAZ gene family and is a candidate for the human Y-chromosomal azoospermia factor (AZF). Its expression is restricted to pre-meiotic germ cells, particularly in spermatogonia. It encodes an RNA-binding protein that is important for spermatogenesis. Four copies of this gene are found on chromosome Y within palindromic duplications; one pair of genes is part of the P2 palindrome and the second pair is part of the

neg: Drosophila hybrid sterility if one sex chromosome of one species has recessive alleles interacting with autosomal alleles of the mating species. This could cause the heterogametic sex chromosome in the hybrid to be inviable or sterile, but homogametic sex chromosome will be fertile (Futuyma 1997). Consequently, in species where presence or absence of a Y chromosome determines gender, for instance, individuals carrying XY chromosomes (males) will be sterile and those carrying XX (females) will be fertile. This is closely related to Haldane's rule. It has also been shown that microbial infections of invertebrates can cause modification of the gender and fertility of host's

neg: Azoospermia factor Azoospermia factor Azoospermia factor (AZF) refers to one of several proteins or their genes, which are coded from the AZF region on the human male Y chromosome. Deletions in this region are associated with inability to produce sperm. Subregions within the AZF region are AZFa (sometimes AZF1), AZFb and AZFc (together referred to as AZF2). AZF is the term used by the HUGO Gene Nomenclature Committee. The AZF1 ("Azoospermia Factor 1") gene is likely located in the euchromatic part of the long arm in Yq11.23. AZF1 is 792kb long and just distal to the centromere of the Y chromosome. AZF1

neg: Calico cat X chromosome. In the absence of other influences, such as color inhibition that causes white fur, the alleles present in those orange loci determine whether the fur is orange or not. Female cats, like all female placental mammals, normally have two X chromosomes. In contrast, male placental mammals, including chromosomally stable male cats, have one X and one Y chromosome. Since the Y chromosome does not have any locus for the orange gene, there is no chance that an XY male could have both orange and non-orange genes together, which is what it takes to create tortoiseshell or calico coloring.

neg: X-inactivation still predominantly expressed from the Xa. Up to one quarter of genes on the human Xi are capable of escape. Studies in the mouse suggest that in any given cell type, 3% to 15% of genes escape inactivation, and that escaping gene identity varies between tissues. Many of the genes which escape inactivation are present along regions of the X chromosome which, unlike the majority of the X chromosome, contain genes also present on the Y chromosome. These regions are termed pseudoautosomal regions, as individuals of either sex will receive two copies of every gene in these regions (like an