DEAR PROFESSOR STRAIN... del 3) Where´s the white?

Bodil Carlsson 17 oktober

eiriasverchjanis@hotmail.com

Till George Strain:

Sorry, forgot two important questions. As I understand it, the S alleles work by restricting migration of pigment cells, thereby creating non-pigmented areas of the body/coat, such as the typical Collie "Irish spotting" pattern. There is a study of some 2 500 British Border Collies published in 2006 which looks at the prevalence of congenital sensorineural deafness, showing an increase in prevalence in merle dogs,dogs with blue irises and "excess white on the head". Is that excess white to be interpreted as one more coincidence effect of the merle gene - it just so happened that a particularly large number of melanocytes with SINES, tails intact, ended up on the head? Or might one suspect that the presence of yet another gene coding for non-pigmentation is important?

The second question is simply this. I run a blog or a net chronicle on dog affairs, genetics amongst them, of which I´m the legally responsible editor. I e, I try to keep it on a level comparable to printed magazines. Lately I have written a few pieces on the merle coat colour, the background being that the National Swedish Kennel Club just has issued a ban on merle/merle matings for all breeds. Also, the Board of Agriculture has recently questioned whether merle is at all a coat colour which is acceptable from an animal protection point of view. The national Collie breed club has banned merle/merle matings for more than twenty years, arguing - as I see it rightly - that the risk for defects in the offspring is too high. There are something like 17% merles among the Rough Collies in this country and whereas no breeder to my knowledge is against the merle/merle ban, several may have found the BoA statement a bit disturbing. It may be my personal ignorance, but I do feel that there are some important questions unanswered concerning the effects/non-effects of the merle gene. If possible, it would be nice to publish an answer to those questions, and if no answer in your opinion is possible yet, because nobody knows enough about the effects of merle, I´d like to publish that, too. In English, of course, and in translation. Would that be all right with you?

Best regards,
Bodil Carlsson