What is the DYZ1 gene?
A human Y-chromosome specific repeated DNA family (DYZ1) consists of a tandem array of pentanucleotides.
Can a male be missing the Y chromosome?
They can be caused by missing or extra copies of the sex chromosomes or by structural changes in these chromosomes. Rarely, males may have more than one extra copy of the Y chromosome in every cell (polysomy Y).
What is the male Y chromosome?
The Y chromosome contains a “male-determining gene,” the SRY gene, that causes testes to form in the embryo and results in development of external and internal male genitalia. If there is a mutation in the SRY gene, the embryo will develop female genitalia despite having XY chromosomes.
Is the Y chromosome the same in all men?
Though a short segment of the X and Y chromosomes are identical, gene sequencing has determined that more than 95 percent of the Y chromosome is unique to males – known as the male-specific region of the Y, or MSY.
What does a boy inherit from his father?
Background: All men inherit a Y chromosome from their father, and all fathers pass down a Y chromosome to their sons. Because of this, Y-linked traits follow a clear paternal lineage.
DYZ1 was the major tandem repeat of the human Y chromosome (Yq12) heterochromatin. Cooke first reported, and Nakahori et al. confirmed, DYZ1 gene was 3564 bp long, and in normal male there were 800–4000 copies,, the majority of which arranged from beginning to end.
How much DYZ1 is deleted in Big Y syndrome?
There was no fraction deletion of DYZ1 detected both in big Y patients and in normal men. Of RSA patients, 1 case showed deletion of 266 bp from the gene locus 25–290 bp, and 2 cases showed deletion of 773 bp from 1347 to 2119 bp.
What determines the distance of unequal crossovers in the DYZ1 sequence?
This indicates that the DYZ1 repeated DNA family evolved and expanded by unequal crossovers which occurred at distances of 3.56kb. As there is a uniformly distributed array of pentanucleotides on this locus, it is not a sequence homology that determines the distance of unequal crossovers.
How many copies of yq12 are there in a normal male?
DYZ1 is the major tandem repeat sequence of the Y chromosome distal heterochromatin (Yq12), 3.6 kb in length [7], 800–4000 copies in normal male [8], and accounting for almost 40% of the total length of the Y chromosome [9].