If a merle parent and a non merle parent produces non merle puppies (i.e. black, black & tan, chocolate etc) are those puppies considered merles? I've been doing a lot of research and read contradictory articles stating there are merle carriers that do not display the merle gene but had a merle parent. Other articles state there is no such thing as a merle dog that does not display merle coloring and although they came from a merle to non merle pair they are safe to breed to merles. Sorry if that's confusing - just trying to learn more on the topic as I find it fascinating!
Any merle experts here? (More info below)
- Thread starter dottiec
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@dottiec I love the merle gene it is very interesting. I'll try to explain it best I can, but if you are interested in reading a study on Merle, I suggest reading "The Incredible Story of Merle". It is a great study, the pdf doesn't cost much, and it has a ton of information.
Anway, merle is a Semi-Dominant gene. Your average gene, like JLPP in Rottweilers, is autosomal ressessive. This means that a dog can be a carrier (Dd) and not be affected in any way. These genes need to be tested to make sure that the parents are not both carriers and could possibly produce any affected (dd) puppies. If one parent is a carrier (Dd) and the other parent is not (DD), there is no way they can produce affected puppies. If you don't completely understand this, definitely look into punnett squares along with Heterozygous and homozygous genes.
Now, a Semi-Dominant gene means that carriers (Mm) look different than the homozygous dominant (MM) and the homozygous ressessive (mm). In this case, merle is the Heterozygous gene (Mm), non-Merle is the homozygous ressessive gene (mm), and double merle is the homozygous dominant gene (MM). Double merle can cause a lot of issues, so we want to avoid that.
A lot of articles may stop right there, but Merle gets a little more complicated. There is also such thing as a cryptic merle. This is where the dog's DNA says they are Merle, but they look like a normal tricolored dog. The merle gene has different lengths. The longer the merle gene is, the more the coat looks diluted or white. The shorter the gene, the possibility you are to not even notice it. This is why it is important to test for merle in breeds that commonly have that color.
Merle may technically be a polygenetic gene, but that gets even more complicated.
Going back to what you said, if you breed a Merle dog and a non-merle dog, will all the puppies be considered merle? No. If these are the parents, the puppies have a 50% chance to be merle and a 50% chance to be non-merle. This is the chance per puppy, so it is completely possible that all the puppies end up being non-merle. Either way, if you plan on breeding them, it is suggested to test just to make sure they are not cryptic merle and the gene is hidden.
Again, if you are interested in this absolutely read "The Incredible Story of Merle". It can be a little complicated, but you will learn a lot.
Anway, merle is a Semi-Dominant gene. Your average gene, like JLPP in Rottweilers, is autosomal ressessive. This means that a dog can be a carrier (Dd) and not be affected in any way. These genes need to be tested to make sure that the parents are not both carriers and could possibly produce any affected (dd) puppies. If one parent is a carrier (Dd) and the other parent is not (DD), there is no way they can produce affected puppies. If you don't completely understand this, definitely look into punnett squares along with Heterozygous and homozygous genes.
Now, a Semi-Dominant gene means that carriers (Mm) look different than the homozygous dominant (MM) and the homozygous ressessive (mm). In this case, merle is the Heterozygous gene (Mm), non-Merle is the homozygous ressessive gene (mm), and double merle is the homozygous dominant gene (MM). Double merle can cause a lot of issues, so we want to avoid that.
A lot of articles may stop right there, but Merle gets a little more complicated. There is also such thing as a cryptic merle. This is where the dog's DNA says they are Merle, but they look like a normal tricolored dog. The merle gene has different lengths. The longer the merle gene is, the more the coat looks diluted or white. The shorter the gene, the possibility you are to not even notice it. This is why it is important to test for merle in breeds that commonly have that color.
Merle may technically be a polygenetic gene, but that gets even more complicated.
Going back to what you said, if you breed a Merle dog and a non-merle dog, will all the puppies be considered merle? No. If these are the parents, the puppies have a 50% chance to be merle and a 50% chance to be non-merle. This is the chance per puppy, so it is completely possible that all the puppies end up being non-merle. Either way, if you plan on breeding them, it is suggested to test just to make sure they are not cryptic merle and the gene is hidden.
Again, if you are interested in this absolutely read "The Incredible Story of Merle". It can be a little complicated, but you will learn a lot.
rubyslippers31
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heretichermes
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@dottiec There’s an informative video on gooddog.com but I’m not sure if this link will take you directly there.
https://www.gooddog.com/good-breeder-center/merle-genetics-with-dr-robert-westra-dvm
https://www.gooddog.com/good-breeder-center/merle-genetics-with-dr-robert-westra-dvm