What are the Pseudoautosomal regions and what is the purpose of them?
The pseudoautosomal region (PAR) is a short region of sequence homology between the sex chromosomes and is involved in sex chromosome pairing, recombination and segregation in meiosis of the heterogametic sex.
Do Z and W chromosomes have Pseudoautosomal regions?
Most regions of mammalian Y or avian W chromosomes (chrW) lack recombination except for the pseudoautosomal regions (PARs) that are shared between X and Y, or Z and W, and which encompass only 2% of the human X (5).
Is the SRY gene in the Pseudoautosomal region?
The SRY transposition into the ancestral eutherian PAR moves several formerly pseudoautosomal genes out of the ancestral PAR making them Y specific and subject to rearrangements and deterioration on the Y chromosomes in simian primates including the human.
Where did the Y chromosome originate?
Classically Y chromosomes are thought to originate from X chromosomes through a process of degeneration and gene loss. Now, the availability of 12 Drosophila genomes provides the opportunity to study the origin and evolution of Y chromosomes in an informative phylogenetic context.
What is Pseudoautosomal genetic region?
The pseudoautosomal regions (PAR1 and PAR2) are short regions of homology between the mammalian X and Y chromosomes. The PAR behave like an autosome and recombine during meiosis. Thus genes in this region are inherited in an autosomal rather than a strictly sex-linked fashion.
Where is the Pseudoautosomal region?
The pseudoautosomal regions (PAR1 and PAR2) of the human X and Y chromosomes pair and recombine during meiosis. Thus genes in this region are not inherited in a strictly sex-linked fashion. PAR1 is located at the terminal region of the short arms and PAR2 at the tips of the long arms of these chromosomes.
What is Holandric gene in zoology?
The genes that are carried on the Y chromosome are called holandric genes. Holandric genes can only be passed by males onto their sons; they code for ‘maleness’ but sometimes cause rare conditions like hypertrichosis pinnae and color blindness.
How do genes in the pseudoautosomal region of the Y chromosome differ from the genes in the male specific region?
Many genes are unique to the Y chromosome, but genes in areas known as pseudoautosomal regions are present on both sex chromosomes. As a result, men and women each have two functional copies of these genes. Many genes in the pseudoautosomal regions are essential for normal development.
