08/26/08 The old grey mare

The old grey mare just aint what she use to be& she might be getting better thanks to genetic research&. I'm Jeff Keane and I will be back after the break with some information that could help prolong the life of grey horses. Grey horses are flashy in the show and rodeo arenas but sadly seventy to eighty percent of all grey horses over the age of fifteen develop skin cancers called melanomas that shorten their lives. Here is Susan Allen with new research on why this color of horse is prone to melanomas. Jeff , according to horse geneticists the reason we have grey horses today is pretty much due to prestige. Thousands of years ago humans began selectively breeding for grey and whites because that is what the leaders and royalty wanted to ride. So, like we have seen in other species, notably dogs, humans create a host of problem when we fiddle with gene pools, in this case breeding specifically for grey horses accidentally passed a gene mutation that predisposes Grey horses to melanomas or skin cancers. Sadly when grey horses age they exhibit an abnormally high rate of skin cell divisions so basically as grey horse lightens it is really showing premature graying. And Susan, we have mice to thank for the fact that researchers are now getting a handle on melanoma in grey horses because they can transfer genes from grey horses into mice then study this graying process more rapidly by breeding transgenic mice with the gene. I'm Jeff Keane.