Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
XY sex-determination system
The XY sex-determination system is a sex-determination system present in many mammals (including humans), some insects (Drosophila), some snakes, some fish (guppies), and some plants (Ginkgo tree).
In this system, the karyotypic sex of an individual is usually determined by a pair of sex chromosomes. Typically, karyotypic females have two of the same kind of sex chromosome (XX), and are called the homogametic sex. Karyotypic males typically have two different kinds of sex chromosomes (XY), and are called the heterogametic sex. In humans, the presence of the Y chromosome is responsible for triggering male phenotypic development; in the absence of the Y chromosome, the individual will usually develop phenotypicaly female. In most species with XY sex determination, an organism must have at least one X chromosome in order to survive.
The XY system contrasts in several ways with the ZW sex-determination system found in birds, some insects, many reptiles, and various other animals, in which the heterogametic sex is female. A temperature-dependent sex determination system is found in some reptiles and fish.
All animals have a genome made of DNA, which forms chromosomes during cell division. In humans, most mammals, and some other species, two of the chromosomes, called the X chromosome and Y chromosome, contain genes which code for sex. In these species, one or more genes are present on their Y chromosome that trigger development of the male phenotype . In this system, the X chromosome and the Y chromosome determine the karyotypic sex of offspring, while genes located on the Y chromosome trigger development of the male phenotype. Offspring usually have two sex chromosomes: an offspring with two X chromosomes (XX) will usually develop the female phenotype, and an offspring with an X and a Y chromosome (XY) will usually develop the male phenotype. Variations such as individuals with Swyer syndrome, that have an XY karyotype yet a female phenotype, and de la Chapelle Syndrome, that have XX chromosomes and a male phenotype, though less common, are exceptions. Additionally, there are several cases of phenotypic females with an XY karyotype (Swyer syndrome), who have successfully hosted a pregnancy.
In most mammals, karyotypic sex is determined by presence of the Y chromosome. This makes individuals with XXY and XYY karyotypic males, and individuals with X and XXX karyotypic females.
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.[citation needed]
Not all male-specific genes are located on the Y chromosome. The platypus, a monotreme, use five pairs of different XY chromosomes with six groups of male-linked genes, AMH being the master switch.
Hub AI
XY sex-determination system AI simulator
(@XY sex-determination system_simulator)
XY sex-determination system
The XY sex-determination system is a sex-determination system present in many mammals (including humans), some insects (Drosophila), some snakes, some fish (guppies), and some plants (Ginkgo tree).
In this system, the karyotypic sex of an individual is usually determined by a pair of sex chromosomes. Typically, karyotypic females have two of the same kind of sex chromosome (XX), and are called the homogametic sex. Karyotypic males typically have two different kinds of sex chromosomes (XY), and are called the heterogametic sex. In humans, the presence of the Y chromosome is responsible for triggering male phenotypic development; in the absence of the Y chromosome, the individual will usually develop phenotypicaly female. In most species with XY sex determination, an organism must have at least one X chromosome in order to survive.
The XY system contrasts in several ways with the ZW sex-determination system found in birds, some insects, many reptiles, and various other animals, in which the heterogametic sex is female. A temperature-dependent sex determination system is found in some reptiles and fish.
All animals have a genome made of DNA, which forms chromosomes during cell division. In humans, most mammals, and some other species, two of the chromosomes, called the X chromosome and Y chromosome, contain genes which code for sex. In these species, one or more genes are present on their Y chromosome that trigger development of the male phenotype . In this system, the X chromosome and the Y chromosome determine the karyotypic sex of offspring, while genes located on the Y chromosome trigger development of the male phenotype. Offspring usually have two sex chromosomes: an offspring with two X chromosomes (XX) will usually develop the female phenotype, and an offspring with an X and a Y chromosome (XY) will usually develop the male phenotype. Variations such as individuals with Swyer syndrome, that have an XY karyotype yet a female phenotype, and de la Chapelle Syndrome, that have XX chromosomes and a male phenotype, though less common, are exceptions. Additionally, there are several cases of phenotypic females with an XY karyotype (Swyer syndrome), who have successfully hosted a pregnancy.
In most mammals, karyotypic sex is determined by presence of the Y chromosome. This makes individuals with XXY and XYY karyotypic males, and individuals with X and XXX karyotypic females.
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.[citation needed]
Not all male-specific genes are located on the Y chromosome. The platypus, a monotreme, use five pairs of different XY chromosomes with six groups of male-linked genes, AMH being the master switch.