|Barked: Sun Apr 12, '09 6:42pm PST |
Kiona pointed me in the direction of this thread, asking if I could lend an opinion. I honestly don't know much about Mals or Sibes, other than the fact that I think they are absolutely gorgeous!
Unfortunately, I don't really have many answers. Genetic research on the molecular level (ie. actually identifying genes and mutations that cause physical traits) is a very new area of science and most research has been done on bacteria, zebra fish, mice, and then applied to humans. Sort of "whatever is easiest, followed by whatever is most 'important'". Dog genetic research is in its very infancy and there are only a very few groups in the world working on dog genetic problems.
We do know that one form of blue eyes in dogs is caused by the merle gene, PMEL17. It results in "heterochromia irides" ... literally, multicolored irises. It most often manifests itself as "blotchy" colored eyes, where there can be both brown and blue on the same eye. Sometimes it appears as if an eye is solid blue or brown, but that is just random occurrence and still considered heterochromia irides if it is present with the merle coat color. Aside from merle, there is no known coat color that is linked specifically to coat color. It is postulated that brown color (ie. the dog has brown nose and pad leather in addition to brown fur) is linked to lighter colored or yellow-ish eyes, but the actual scientific mechanism behind that isn't determined, and it remains in the realm of breeder lore.
Solid blue eyes (either one eye or both) can occur in a number of breeds, but is often not accepted. Something to consider when it comes to breed standards ... if a color is mentioned in the breed standard as being unacceptable, that most often means that at some point in the breed history that color was present in the breed but modern breeders have decided that they don't want the color anymore. Otherwise, why would they mention it? So, I haven't checked out the Mal standard, but if it states that blue eyes are not allowed, I would wager to bet that at some point in the breed's history blue eyes WERE allowed and that it is just a "recent" decision to not allow blue eyes for one reason or another. If the breed NEVER had the occurrence of blue eyes, now or in the past, then there would be no need to mention that trait at all in the standard, as it would never appear naturally anyways.
Based on that, IF blue eyes is counted as a stated disqualification in Mals, I certainly wouldn't say that it is impossible for a Mal to have blue eyes. That trait was likely present in the breed at some point and there is a possibility of it cropping up randomly again.
As for the gene that causes solid blue eyes ... we just don't know yet. There is no way to test a dog to see if it carries the mutation that causes blue eyes because we don't know what the causative gene or causative mutation is.
Hope that helped shed a little bit of light on the situation. Even if there are no real answers yet!! haha
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