Do we really need the chromosome Y ?

Do we really need the chromosome Y ?

In humans , sex is determined by two chromosomes X and Y. A pair of X gives daughter X and Y a boy. But , while the X carries several hundred genes useful in other compartments of the body that the genital system , the Y- rich is far less . He lost many genes since its appearance in the world of the living , and even if this degeneration seems stopped for about 25 million years , the Y chromosome gives the impression of being curled , concentrated on his " heart of business " , namely to determine the male and manufacture sperm. Hence the question posed some geneticists : How many genes are needed for this double task?

If you believe a U.S. study published by Science on November 21 , the correct answer , at least in mice, is the minimum response : two missions, two genes. The team from the University of Hawaii who wrote this article has used the architect Sry that in utero triggers differentiation of the embryo by directing its gonads during manufacturing towards testicular gene. Simply, these researchers knew it needed add at least another gene because even male appearance , individuals thus obtained would be sterile , sperm production is incomplete home. They therefore have the added Eif2s3y gene in mice , the process unlocks spermatogenesis .