Golden Girl was the rabbit that really got me curious about genetics. I was completely new to concept so this article walks through my discovery as I learned. We had been crossing New Zealand Whites and Silver Foxes for about a year getting mostly brokens (spotted), blacks, and blues. We got a black kit that did not quite look as black as a sibling within a few days from birth. When her fur grew out, we could see the hair shaft was banded ending with gold tips. After I made an inquiry on a rabbit message board, I was told she was a Black Gold-Tipped Steel and that her genetics would be:
GT Black Steel
A_ B_ C_ D_ Es_
From the Sire
I now know more about Golden Girl's genetics than most of my rabbits, but it started with me filling in some of those blanks by looking at the parents. Actually, her New Zealand White father does not help me out at all with narrowing down what she could be. Red-Eyed Whites are full of wild cards, because the C-locus has to have double recessive "c" genes that will cover all the genetics, like snow will turn everything white and covering the colors of everything. So all I will know is there will be a potential of any possibility because of that "cc" trait.
NZW
__ __ cc __ __
Perhaps on a side note with my NZW buck, I know that he carries the dominant broken gene En, because every time I bred him with my Silver Fox doe, I got about half as Brokens. The "En" Broken gene cannot hide, except when it is covered (by snow) with the "cc" white genetics. In other words, if my Silver Fox doe had "En" in her genetics, she would be broken. I learned that the father also has a recessive "en" gene because not all his colored offspring were Broken. Since it is not a factor, it was not necessary to know in regards to Golden Girl's genetics, but I found it interesting.
My NZW Buck
__ __ cc __ __ Enen
From the Dam
Misty Blue came with a pedigree from a breeder who placed genetics on it. That is the way a pedigree should be, in my opinion. It does not guarantee the breeder knew all the genetics, but at least a person can look it over and understand the possibilities.
- All Silver Foxes must have two recessive "aa" in the A-locus.
- All Blacks and Blues must have at least one dominant "B" in the B-locus.
- All Silver Foxes showing full colors must have at least one dominant "C" in the C-locus.
- All Blue Silver Foxes must have two recessive "dd" in the D-locus.
- All Silver Foxes, not expressing Tort, must have at least one dominant "E" in the E-locus.
This is the baseline of all Silver Foxes showing blue and the recessive broken genes are not usually even considered because they are not seen.
Blue Silver Fox
aa B_ C_ dd E_ sisi (enen)
In the case of my Blue Silver Fox doe, Misty Blue, I also know that she probably does not carry a recessive "c" because in all our crossbreeding, we never saw a REW from her, but I did learn that she carried Chinchilla.
Misty Blue
aa B_ Ccchd dd E_ sisi (enen)
Golden Girl's Genetics
Looking at the base genetics for a Black Gold-Tipped Steel and applying the genetic rules that she gets one gene from each parent in each locus, I know for a fact that Golden Girl had to get a recessive "a" and a recessive "d" and a recessive silvering gene "si" from her mother, as well as a full-color "C." From her father, she also had to have a recessive "c" gene and a dominant non-silvering "Si" gene.
GT Black Steel
Aa B_ Cc Dd Es_ Sisi enen
I now only have two questionable loci with Golden Girl. I did not know if she is in fact Agouti as I was initially advised that she had to be. I read somewhere that even an "aa"-Self with EsE will show Steel, but it was believed in such cases that a slight steel coloration would be seen around the nape and lower flanks/chest and otherwise would be self-colored because a self rabbit would lack Agouti ticking. Whether correct or not, that does not describe Golden Girl so she must have Agouti from her New Zealand father, which is expected, and I know she received the recessive "a" from the mother.
The second in question is the B-locus. It is unknown if she carries a second dominant "B" so she could only produce Blacks and Blues or if she have a recessive "b" so that she could produce chocolates bred with a buck also carrying the recessive "b" or lilacs when bred with a buck carrying recessive "b" and "d." I did not know the genetics of the bucks enough to eliminate that either way, but I have not had a chocolate or lilac from her yet. If I had a chocolate or lilac buck to breed with her, I would have better odds of knowing.
The second in question is the B-locus. It is unknown if she carries a second dominant "B" so she could only produce Blacks and Blues or if she have a recessive "b" so that she could produce chocolates bred with a buck also carrying the recessive "b" or lilacs when bred with a buck carrying recessive "b" and "d." I did not know the genetics of the bucks enough to eliminate that either way, but I have not had a chocolate or lilac from her yet. If I had a chocolate or lilac buck to breed with her, I would have better odds of knowing.
However, the known diversity in Golden Girl's genetics makes her good for testing breeding to reveal some hidden genetics in NZW and SF bucks. For instance, if any color of Silver Fox buck was carrying a recessive "c" then they would likely produce a REW kit. If a Black SF is carrying a recessive "d" then they would likely produce a Blue kit. If they produce a Chocolate kit, then both would be carrying a recessive "b," even if neither one shows it. I will not even try to explain every possibility a crossbreeding with an NZW could produce because of all the wildcards, but in Golden Girl's recent breeding with an NZW, she had two REW, a Black, and a GT Black Steel. Having only four kits, in this case, did not really tell me anything for certain, other than the buck may not be carrying the "En" broken gene because the two with color were solids.
I could also breed Golden Girl, who is NZW/SF 50/50 with a Silver Fox buck having "sisi" and because she has the recessive silvering gene "si," her kits should silver. However, the silvering gene is not well researched and I have come to disagree with it being recessive. Through crossbreeding, I have found that the silvering gene is more likely dominant or as some say an "incomplete dominant" gene. In other words, if one parent is silvered, the offspring will silver to some degree.
Back to the Sire
Knowing the genetics of Golden Girl and seeing her offspring filled in a blank on her NZW father's hidden genetics.
- Golden Girl is not diluted, which creates Blues and Lilacs, so she had to get a dominant "D" from her father.
My NZW Buck
A_ __ cc D_ Si_ Enen
Golden Girl was an Agouti, so she would have gotten that from her NZW father as well.
Steel Gene?
From whom did the steel "Es" gene come from? I read it somewhere that it is considered a sneaky gene, because it is always dominant but still can be hidden. It could have come from either the mother or the father because they both could have genetic factors to hide it, since it is commonly thought that the rabbit must have Agouti "A" or otter "at" for steel to present. Under that assumption, Steel cannot be seen on a Silver Fox because of the double recessive "aa," although some genetics experts believe that "aa" will show Steel if also "EsE" is on the E-locus However, Steel absolutely cannot be seen on a REW because of the double recessive "cc" that covers all genetic color variations like a blanket of snow.
It is more likely the steel gene came from the NZW father, although that is very hard to prove when after crossing different combinations with the mother and the father for two years, only one Black Gold-Tipped Steel (GTS) was produced. Even when I bred Golden Girl back to her father, I did not get any Steels, but I did not pay close attention to the color spots on my brokens, so I might have and did not make a note of it as I was not keeping records on colors then.
I have since learned that while Steel is pretty, it is not an accepted color except for a few rabbit breeds and it is not really something I want to work with in the future, but Golden Girl has been a good producer and mother, plus it was kind of fun trying to figure all this out about her genotype, so absolutely no regrets there.