NEW YORK, June 20 - Large chunks of the Y chromosome read the same forward and backwards, providing it with a mec
Researchers from the Whitehead Institute and the Department of Biology at MIT, the
Once class of sequence, called "X-transposed," appears to have moved over from the X chromosome within the last few million years and still bears about 99 percent identity to the corresponding X sequences. The second class, dubbed "X-degenerate," is more distantly related to the X chromosome and seems to derive from an ancient common ancestor of both X and Y. Finally, a series of eight large palindromic sequences - sequences that read the same in either direction -- makes up the third class, called "ampliconic."
These palindromes can undergo a form of recombination called gene conversion, where one arm of the palindrome "converts" its counterpart to a copy of itself - a way for the Y-chromosome to prevent its sequence from degenerating. The scientists found this mec
Their analysis, the researchers say, may help understand the genetic basis of male infertility, as well as a female chromosomal disorder called Turner syndrome, where one X chromosome is missing.