|MadSci Network: Genetics|
Apologies for the delayed reply! I just discovered the message in my spam folder on receiving a reminder. The tempting answer would be epigenetic modification. The foal is genetically identical to the mother, but it's possible that methylation or other alterations to the DNA have resulted in a different phenotype. That's the tempting answer, and would probably get me full credit on a genetics exam. But I think there's a better one. Charles Darwin mentions in _The Origin of Species_ that the coloration of mules' legs can change as they grow older - might not the same hold true for horses? Google show it to be so! http://www.geocities.com/SoHo/Studios/2905/foals.html Relevant bit: "Point colors are unreliable indications of adult color as many foals are born with almost colorless mane & tails. Many foals will not show signs of their adult color until after the first shed. Lower leg colors on horse foals are almost always lighter, generally ranging from silver to beige." So, the reason the clone doesn't show its mother's leg color is that it is freshly cloned, and so much younger than its mother. Should it survive to be as old as its donor is now, I expect that its legs should change color to match. I hope this clears that up, and again, sorry for the delay. Paul Nagami
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