Recombination between the X and Y chromosomes proved harmful—it resulted in males without necessary genes formerly found on the Y chromosome, and females with unnecessary or even harmful genes previously only found on the Y chromosome. As a result, genes beneficial to males accumulated near the sex-determining genes, and recombination in this region was suppressed in order to preserve this male specific region. Over time, the Y chromosome changed in such a way as to inhibit the areas around the sex determining genes from recombining at all with the X chromosome. As a result of this process, 95% of the human Y chromosome is unable to recombine. Only the tips of the Y and X chromosomes recombine. The tips of the Y chromosome that could recombine with the X chromosome are referred to as the pseudoautosomal region. The rest of the Y chromosome is passed on to the next generation intact. It is because of this disregard for the rules that the Y chromosome is such a superb tool for investigating recent human evolution.
Darren Griffin has current collaborative grants with JSR Genetics and Topigs Norsvin. Including BBSRC and Innovate UK funding.
Enhancing oocyte quality to improve assisted reproduction in peri-pubertal pigs and cattle (BBSRC) - About to start. £335,000
Technology Strategy Board (BBSRC - Inovate UK). Pig IVF and genetics: A route to global sustainability.