> Hmmm - coming late to the conversation, and probably missing a few of the posts, but I do wonder how one can breed by genotype, since it seems to be pretty much impossible to know all the genes in a given dog's makeup. On the other hand, every breed in the world, warts and all, was developed > basically by breeding phenotype...and in some cases, with a care to working ability.
Although everyone can breed by phenotype, it is actually the successful ones who breed by genotype. The more you know about relatives of a dog, the more of that genotype you know. This is not a black and white issue--it can be all shades of gray as well. You may know nothing, a little, some or a lot about a particular dog's genotype for a certain trait--but the more you know, the more successful you will be in breeding from and to that dog. When one says I want to breed to Ch. Nearly Always Produces a Good Head--they do so more because of his genotype for heads, not his phenotype. Whenever a particular kennel is well known for a *look* it is more because of genotype, not phenotype. They have phenotypically bred that look so much and in such a way, that the genetic makeup of their dogs has become such that most of their puppies look the same way--their genotype is somewhat known. We know fewer genes are *hidden* because fewer and fewer of the dogs turn out looking very different. In other words phenotype has become more strongly genotype. Linebreeding done corrrectly/intelligently is breeding more on genotype rather than phenotype. If we linebreed to *keep* a certain look and are successful it is more because of genotype, rather than phenotype, that we were. The genotype of most top stud dogs is much better known than the average dog because they have enough offspring that one can get a good idea of what much of their genotype is for certain traits. Actually, the REASON they become top stud dogs is because we have figured out much of their genotype for certain traits, found this genotype for those traits is very desirable, and want to breed those traits into our own dogs. Here is a good example: my own dog, Finley is 13 inches tall and weighs about 18 lbs. He is considered on the larger side by some. That is his phenotypical expression of size. Many people have inquired about using him on their small bitches because it seems his size (besides whatever other qualities they perceive in him of course) would be a good match for them and maybe they would get more size. But Finley has had enough litters now by a variety of different sized bitches from different lines that I can clearly see his genotype is for small. 80%-90% of his puppies have been on the small side--some quite small. When bred to small bitches, he produces teeny tiny. Yes, bigger ones turn up now and then, but they are in the minority. (And of course there are bitches whose genotype is so strongly towards big that nothing will impact on that!) If I bred him phenotypically it would not be good. He could be a much more successful stud dog if NOT bred to very many small bitches--if bred on his genotype. Of course we are only talking about size here, one may want to breed to a dog for other reasons and accept the *size* (or whatever) that comes with it. It really was not that hard to see that small is his genotype for size after several litters--it honestly didn't take a rocket scientist to figure it out. Do we fully know all his genes regarding size? Of course not. We don't need to. We can see that he produces small the vast majority of the time so we have a very good idea that his genotype is *geared* to small. And we can choose to use that information if we so wish. The more information that is shared about ALL the dogs breeders produce (not just the show dogs), the more able we will be to breed by genotype. It is possible! If we are all open and share this information. Of course all still has to be within reason. Genetics is quite complicated and it is possible/probable you can only go so far towards creating such similarity before self-destructing. By being open and honest with others as to what is happening though it should be easy to see when we are nearing this line. Laura Trunk Roycroft Cavaliers ========================================================= "Magic Commands": to stop receiving mail for awhile, click here and send the email: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20NOMAIL to start it up gain click here: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20MAIL E-mail [EMAIL PROTECTED] for assistance. Search the Archives... http://apple.ease.lsoft.com/archives/ckcs-l.html All e-mail sent through CKCS-L is Copyright 1999 by its original author.
