Alicia Posted October 24, 2006 Report Share Posted October 24, 2006 I was browsing the White Factor posts.. and noticed everyone calling them "Lethal" whites.. If they are "Lethal" wouldnt they be dead.. as in Horses a Lethal White (aka LWO or OLW) cant live. They die or have to be Euthanized (LWO are not to be confused with Cremellos and Perlinos) I've done extensive genetic research on horses, Know all about the genetics behind almots every color... BUt... Since White Border Collies exsist, are alive and well save the merle to merle breeding that can result in deaf and blind pups..but none die.. Why are they referred to as "Lethal"? Quote Link to comment Share on other sites More sharing options...
Rebecca, Irena Farm Posted October 24, 2006 Report Share Posted October 24, 2006 Many merle/merle pups die. Some die in utero, and others die shortly after birth (suffering). I always assumed "lethal" refers to the fact that it can lead to unviable fetuses. Like the gene that produces hairlessness in my chinese crested. It's a dominant lethal like merle. Pups homozygous for the gene can't even be born alive. Merle isn't that bad but it can be for some individuals. Quote Link to comment Share on other sites More sharing options...
Eileen Stein Posted October 24, 2006 Report Share Posted October 24, 2006 > Not everyone. "Lethal white" is simply a misnomer as applied to dogs. Quote Link to comment Share on other sites More sharing options...
Pipedream Farm Posted October 25, 2006 Report Share Posted October 25, 2006 "White Factor" is a term to describe a pattern of white coloration that when bred to another White Factored dog often leads to offspring with more white on the body than the parents. There's nothing lethal about it. Mark Quote Link to comment Share on other sites More sharing options...
Pat W. Posted October 25, 2006 Report Share Posted October 25, 2006 I know in Aussie merle x merle breedings that usually result in at least a few white factored pups, the breeder will cull these babies at birth as they are usually born deaf, blind or both making them unsellable, if they are born alive at all. Im guessing that its the same for bcs although the merle x merle may not be as prominent in the bc world as it is unfortunately in the aussie world. I remember many a time when the list would go up in flames when someone brought up the subject of merle x merle breeding and wanting advice on doing it. It was like chumming the water for sharks..not a pretty sight Quote Link to comment Share on other sites More sharing options...
Eileen Stein Posted October 25, 2006 Report Share Posted October 25, 2006 Pat, you're right that merle x merle produces white or mostly white (not "white factored") puppies which frequently have defective sight and hearing in border collies as well as in Aussies. (You're also right that it's much less frequent in border collies, because merle itself is much less frequent, although with puppy millers pouring out merle BCs nowadays it may become more frequent.) I think people may use the term "lethal white" to describe that condition, and distinguish it from the extreme white-factoring Mark is referring to, which results from an entirely different gene. But it's sort of slang or shorthand, and not accurate. Quote Link to comment Share on other sites More sharing options...
Pipedream Farm Posted October 25, 2006 Report Share Posted October 25, 2006 Another example of the confusion that comes with undefined (or not universally accepted) terms. The Border Collie Museum has lots of photos. There is a section of PATTERNED WHITE dogs. In the BLACK & WHITE section there are photos of dogs that are what I would call "white factored" (white up the inside of the back leg); for example Skye. When two white factored dogs are bred, Patterned White offspring are likely to be produced. Mark Quote Link to comment Share on other sites More sharing options...
juliepoudrier Posted October 25, 2006 Report Share Posted October 25, 2006 I just want to point out that when I went back and looked at some of those old threads, there was one poster who asked if her dog was a "lethal white." I didn't see any confusion as to what lethal white refers to (double merle dogs). That is, "everyone" was not calling white factored dogs "lethal whites". As others have pointed out here, lethal white has nothing to do with white factored. The genetics of white factoring really is fascinating. You can breed two white factored dogs and get pups with a lot of white (patterned white) or pups with little or no white (or simply classically marked). Eileen, in your research have you ever come across a site that explains the "whys" of that? J. Quote Link to comment Share on other sites More sharing options...
Liz P Posted October 25, 2006 Report Share Posted October 25, 2006 Yeah, what I want to know is why you sometime get dogs with almost no white on them when you breed white factored dogs together. Quote Link to comment Share on other sites More sharing options...
Alicia Posted October 26, 2006 Author Report Share Posted October 26, 2006 Ok, so it seems I may have been confusing posts on Merele to Merele "Lethal Whites" with "White Factor" posts. I could've sworn I saw a post on White Factor with the term "Lethal White" used frequently but I cants find it now But, regardless, I hadnt considered Merle-Merle as Lethal as I thought the dogs survived but were just deaf and/or Blind. This was cleard up Some die/may die in utero, some die shortly after birth, some are culled and few survive these situations That why it's termed "Lethal" I see now Thanks guys So my girl, Dally is the result of a White Factor, White factor breeding. Both her parents had extensive belley side and collar white. and she is heavly white factored as the pics show (see, Gen Discussion about Whites with black on face) Thanks guys for clearing that up for me Quote Link to comment Share on other sites More sharing options...
Alicia Posted October 26, 2006 Author Report Share Posted October 26, 2006 Pardon my typos, I'm cold and so shivering slightly and typing fast equals bad grammar and spelling lol that and my mouse keeps clicking for no reason, changin my typing area Quote Link to comment Share on other sites More sharing options...
Eileen Stein Posted October 26, 2006 Report Share Posted October 26, 2006 > Julie, the best site I know of with a general discussion of white factoring is http://bowlingsite.mcf.com/Genetics/ColorGen.html . Scroll down to the discussion of the S locus (although there's plenty of other interesting stuff you'll be passing before you get there), which is the white-factor gene series. The action of the alleles at the S locus is not very well understood. Hopefully, that will soon change now that we can work directly with the canine genome, but up to now, color genetics has been pretty much based on hypothetical constructs derived from observed results of various matings. These results do not always fit perfectly with the constructs, which leads to the tentative conclusion that there are various modifier genes which affect the expression of the basic S alleles. Different modifiers, or different distribution of modifiers, appear to be present in different breeds, and of course each of the pups in a single litter may inherit a different complex of modifiers. The genetics of white-factoring has long fascinated me, and I can't wait for us to have a fuller and better explanation of it. Quote Link to comment Share on other sites More sharing options...
Alicia Posted October 26, 2006 Author Report Share Posted October 26, 2006 They need tests for color like in horses ;D Quote Link to comment Share on other sites More sharing options...
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