The mammalian sex chromosome Y , responsible for assigning the male gender, is evolving faster than previously thought , according to a new study from the Whitehead Institute in Cambridge (United States).
Its authors, led by David Page, completed the sequencing in the chimpanzee of the male-specific region of the Y chromosome (MSY) and compared it to the equivalent sequence in humans. The two sequences differed radically (up to 30%) in structure and genetic content, indicating rapid evolution.
The discovery contradicts the idea that Y chromosomes are essentially tight structures that evolve very slowly and only due to genetic loss. On the contrary, everything points to the fact that permanent renewal and remodeling mark the evolution of the human and chimpanzee Y chromosomes. The researchers compare the transformation of the Y chromosome with that of a house in continuous reform : "Its inhabitants continue to live in it, but there is always a room under construction. And this is not the tone for the rest of the genome," explains Page. However, not all of the Y chromosome evolves at the same rate. The fastest evolving region of the chromosome is that involved in sperm production .
