German Shepherd Dog > breeding snafu? Help! (64 replies)
by fzarkowski on 30 August 2009 - 13:54
|It looks as if the situation will be cleared up without any difficulty. ALL thier dogs are very nice, so it's all good!|
by darylehret on 30 August 2009 - 15:59
|Agouti is not a color or pattern itself, but refers either to the loci or allele series. The agouti locus on the chromosome is where the pairing of any two of the alleles coding for color pattern are located, of the allelic types aw, as, at, & a (ay series is not found in the german shepherd breed). As stated by molly, the most dominant of the two in a pair that a dog posseses, is the one phenotypically expressed.|
A dog of this color pattern (phenotype) can have these allele pairs (genotype)...
Black & Tan (as)
This means that a sable cannot be produced without a sable parent (nor from black & tans or from bicolors, as some would argue)
by luvdemdogs on 30 August 2009 - 17:25
|I don'tthink that is quite correct. I'm going waaaayyyy back into my university biology classes with some help from that site and will describe how I understand dog color genetics. |
A "locus" refers to a place. (thank god for my smidgen of latin, LOL) Think of the word locus as location and one would get a better idea of the concept. A locus actually specific place on a strand of DNA that the color genetics occurs. There is actually an A locus, a B locus, a G locus etc, but the genetic color code is different than the locus. The same letters are used to show where on the DNA strand it occurs, but the use of letters themselves (capitalized or lower case, reused) show what color and how it will be expressed in terms of what it will look like and where the colours will be on the dog.)
The structure of DNA is such that there are polymers of substances called nucleotides in a double helix pattern. The variants of the combinations of those nucleotides in various patterns basically contains the map or blueprint of a life itself and it's expression., whether it be expressing itself as a frog or a human, with green skin, white skin, hair, or color.
At the point on the DNA chain that the color gene occurs for dogs, there may be several chemical variants that give rise to the colour and it's various expression.s (that is, what color (s) will the dog be, and how and where will those colors occur. That grouping, so to speak, is called a "series" because it is not simply one simple nucleotide at one locus - it is a complex group of chemicals occurring in various patterns..
By the way, in my view, if anyone says this is "plain and simple" is fooling themselves. it is anything but plain and simple.
The dogs color genetic consists of several different patterns of the nucleotides at the location ("locus") that the informational material occurs.
"Agouti" does not refer to a locus or a series. Agouti patterning occurs as a RESULT of the various series of nucleotides in combination.
Ay is sable. Sable is characterized by the capital A. The small a refers to agouti.
aw is agouti
aw +aw could only produce agouti, not sable.
I believe, in reviewing the some of the posts, the term "sable" used may be used incorrectly, when "agouti" is a more correct term - but it is within the GSD community - not other dogs that agouti is called "sable" - totally confusing. It appears that the "agouti" expression is typified by single hairs of more than one colour.
by firefly on 30 August 2009 - 17:32
|Both dogs are owned by Old Farm Kennels in Connecticut http://www.oldfarmkennels.com/Ourdogs.html|
by crhuerta on 30 August 2009 - 17:35
|Why not simply invest in Malcomb B. Willis's book on the Genetics of the German Shepherd Dog.?|
He lists all the genetic variables in "color, coat etc...etc...".....from which the breed was created..
It's a great book, it's a learning book, and a must for GSD breeders....I believe.
by TessJ10 on 30 August 2009 - 17:46
|Glad it's going to be cleared up.|
I have a question, though, that's not related to color. Are their dogs also AKC registered? I saw on their website that they charge "a $100 fee" to transfer ownership on AKC papers. If the parents are not AKC, then I guess they want to be paid for the paperwork to make AKC happen. But if the parents ARE AKC registered and ownership is transferred, seems you should get the papers when you buy your puppy.
by luvdemdogs on 30 August 2009 - 18:12
|Sheila Schmutz at he University of Saskatchewan has updated it as at August of this year. She looks at the various books on genetics and says this about Malcom B Willis's book, among others|
:"Two classic books tell us much about the inheritance of coat colors and patterns in dogs. The one most quoted is by Clarence C. Little, The Inheritance of Coat Color in Dogs, Howell Book House, 1957. The other is by Ojvind Winge, Inheritance in Dogs with Special Reference to the Hunting Breeds, Comstock Publishing, Ithaca, N.Y. 1950. A third book, Comparative Genetics of Coat Colour in Mammals, by A. G. Searle, Logos Press 1968 is also a useful resource. This page is organized by the coat colors or pattern names and the gene loci postulated by Little are included where possible. Molecular studies are showing that Little was usually correct in his hypotheses, but not always.
"Many people read a more recent book by Malcolm B. Willis, Genetics of the Dog, Howell Book House, New York. 1989. His terminology is different for several alleles than that of Little. This leads to some real confusion for people who try to read several books or webpages designed by people who have read some of these books. All 3 of these books are out of print so they are difficult to purchase, but try your local library. There is a chapter in a book called The Genetics of the Dog edited by A. Ruvinsky & J. Sampson, CABI Publishing but sold through Oxford in North America, which contains a chapter by Philip Sponenberg and Max Rothschild on coat color. This book is still for sale by order at firstname.lastname@example.org.
None of these books contain DNA studies however. All are based on hypothesized alleles at hypothesized loci to fit data obtained from coat colors and patterns of dogs from various breeds and litters. DNA research has shown that there are more genes involved than those hypothesized by these authors and that the actual number of alleles at genes they discuss is more for some genes and fewer for other genes. An invited review paper on the DNA research on the genes known to be involved in coat color was published December 1, 2007 in Animal Genetics, with the photo page shown above.
I was quite surprised to see that there appears to be no dominent Ay according to this author.
by crhuerta on 30 August 2009 - 18:51
|Ok.....again...why not buy books on the subjects?|
I just added a couple that you posted to my list of must reads......
by darylehret on 30 August 2009 - 19:45
|That's pretty much what I said luv, agouti is the locus or the series of alleles into which it fits.|
by darylehret on 30 August 2009 - 19:51
|aw is "wolf grey" sable, not "agouti".|
by luvdemdogs on 31 August 2009 - 01:10
|Sorry Darryl, I think you're incorrect. Agouti is a color scheme located on the A locus. It is not the locus. Recessive blacks are also located at the A locus. There are different letters used for sable but technically, I believe the "ay" is sable and "aw" is agouti - which may show up as a wolf grey and be called "sable" in the german shepherd world. It looks like the german shepherd world uses it's own preferences for language (just as it does with the redundant word "dog" at the end of the name, LOL). Realistically, all dogs should have the same language because it's all genes, but it seems we call agouti dogs sables. I know I always have c alled them sables, but have only just started studying the genetics behind coloration because I was interested in the white and dilute phenomena. Agouti refers to banded hairs - that is what shows up in the wolf color sables.|
by luvdemdogs on 31 August 2009 - 01:34
|In terms of dominance, it appears that clear sable "ay" is dominant over the wild sable "aw" which in turn is dominant over the black and tan "at" which is dominent over the recessive pure black "aa". |
It's all totally fascinating....
by fzarkowski on 31 August 2009 - 02:04
|Oh, I wish the name of the kennel had not been put up. I don't know what happened, and if she turns out to be out of these two, I will let you know. The issue is being taken care of, so there is no longer a problem. All I can say is they have wonderful dogs in impeccable condition. If I was ever in the need of another dog, I would love to get one of theirs. This puppy I have is so bright and focused at 12 weeks of age. She is nothing but a complete joy to work with. She's self confident, and so well adjusted. You just couldn't ask for a better temperament. Plus, she is a complete velcro dog. I would still reccomend their dogs to anyone. As I said before, things happen. I want to get into schutzund with this girl, and I went to talk to a trainer. I knew he would want to know her pedigree, so I ran it off from this web site. I was basically humiliated when he told me about the genetics involved. I should have known better. I breed horses. I know grey is dominant. I didn't know that sable was dominant in GSDs. I had been looking for a dog for 2 years, and this one is the only one that I really wanted. And she still is. I really do recommend them.|
by crhuerta on 31 August 2009 - 02:18
I don't think you need to appologize or feel bad about your post.......you said nothing wrong about the breeder.
I don't believe anyone else has either....?
I'm sure things will work out for the best!
by darylehret on 31 August 2009 - 03:41
The A locus is the agouti locus or ASIP locus. The A series is the agouti series, comprised of several possible allele types, not just in german shepherds, but in other breeds (i.e., dobermans) and species (i.e., mice, pigs). Not all allele types (within the agouti series) are available in the genepools of each breed or species. One of which found in GSD's is a loss of function allele or null mutation known as "nonagouti black" or "recessive black"or "a", one of which isn't the ay allele which codes for a phenotype known as "fawn" or "golden sable" found in other breeds.
by darylehret on 01 September 2009 - 12:59
I'm going to play devil's advocate here, by challenging these statements made by Molly and I earlier in this thread, by saying there is a possibility, albeit a very very slim one.
Mutation is the fundamental process that gives rise to new gene variants or alleles within a series for expression at a given locus. Mutations are typically recessive in form, and often harmful when homologously paired. Alleles that code for black&tan/bicolor and solid black coloration in the German shepherd dog are such variants from the original agouti wild-type (Aw) that are however not harmful when homogenously paired.
Reverse Mutations are also known to occur, for example at the agouti locus in mice studies, in which the wild-type phenotype is restored; such organisms are called revertants. This is also known as "back mutation" or "reversion mutation." Even a more dominant variant of an allele series can revert to it's less dominant wild-type phenotype (i.e., Ay reverse mutate to Aw).
by darylehret on 01 September 2009 - 13:02
by Samba on 02 September 2009 - 02:44
|Oh, yes, a mutation could occur. The Pandas show us color mutation. One might have been saying you can't get a tri-color dog out of two black and tans then. It is a very small chance though, but "anything is possible, my child".|
by eichenluft on 02 September 2009 - 04:17
|would like to see the sable dogs proven (with DNA) to be produced from non-sable parents. Anyone? One dog? Come on Daryl - surely if there is any chance at all, in the 100 years that the breed has existed there must be one. One sable dog from non-sable parents - proven of course to be true and not a theory that it "could happen"?|
by Kalibeck on 02 September 2009 - 05:15
|What about rare occurences....I was reading about how rare tri-colored males cats are...something like 1 in 8 million...because the color pattern is linked to the y chromosone...so a male tortie or tri would have to have xxy, an extra chromosone....does anything like this happen, or could it happen, in the GSD? This stuff is fascinating, I'd really like to know...jackie harris|