Bunnylady
Herd Master
OK, I'll try this again. I have a migraine/sinus headache going on, so I may not be very coherent - please bear with me!
Within all the instructions of a rabbit's genetic code, there are a bunch of genes that influence coat color, one way or another. For every trait, a rabbit has two genes that control it, one that came from the mother, one that came from the father. If the rabbit inherits the same form of a gene from both the mother and the father, we say it is homozygous. If the two forms are not the same, the rabbit is heterozygous for that trait.
A dominant gene is one that, if a rabbit inherits it, you will see its effects. It can't hide. A recessive gene "takes a back seat" to a dominant; to see it, you usually need the animal to have inherited the recessive form from both of its parents - in other words, to be homozygous recessive. Most of the time, you can't tell if an animal is homozygous or heterozygous when the dominant form is present, because it looks exactly the same. There are exceptions, and rabbit coat color has several remarkably different examples of this. One is the broken gene.
In a discussion of rabbit coat color, the broken gene is symbolized En. This is because it was first identified in the English Spot breed. Animals with the broken gene generally have white on their feet, their bellies and chests are (at least mostly) white, and there is usually some white on the face and tail. There are a whole slew of modifier genes that fine tune the exact appearance of any particular rabbit with the broken gene. People with breeds like English Spots and Checkered Giants are very picky about just which form the modifiers must be, and want the markings to look just so. Most other breeds that employ the broken gene are not as selective, allowing a much greater range of expression in their brokens. The two kits (broken red and tricolor) that you posted pics of appear to be quite typical, acceptable MR brokens.
There appear to be only two possibilities at the En locus (the place where the broken gene happens), En (broken) and en (not broken [solid]). En is dominant, so an animal with one copy of each (heterozygous) will be a broken. A solid is clearly enen, homozygous recessive. Curiously, there is a marked difference between the appearance of a heterozygous broken, and one that is homozygous. The EnEn rabbit has very little color on it at all. There usually is some color on the ears, some around the eyes, and little or none on the nose. There is very little color on the body, as well. These animals are often called "Charlies" (I've heard it is because the small mark that they may have on the nose reminded someone of a Charlie Chaplin moustache). Because the Charlie has only the dominant En form, all of its offspring will inherit the broken gene from it, and be brokens.
The harlequin gene (eh) is found in the E series. There are a couple of other genes in this series that are dominant to it, but only one (e) that is recessive. e is the "non-extension" gene, the one that gives you red and tort. The harlie gene is kind of weird, in some places it acts like the non-extension gene, and removes black from the hair shaft, and in other places it acts like the self gene, flooding black all over the hair shaft. Like the broken gene, the harlie gene sets the pattern, there are other genes that modify the way the pattern gets expressed. I breed Harlequins (the breed) and I have seen even pedigreed, homozygous Harlies with barely more pattern than the black streak you describe your buck as having. He sounds like a harlequin to me.
Tricolors, of course, are nothing at all but broken harlequins. There are several breeds that recognise tricolor for the purpose of showing, but not its solid counterpart, harlequin (I'm sure it makes sense to someone). Other than it being unshowable, there is no reason to exclude a harlie from a tricolor breeding program. If you are trying to avoid producing the nearly all-white, EnEn Charlies, you would breed solid to broken. Since the "good" broken is Enen, some of the offspring are bound to be solids. If you are trying to breed showable tri's, the best way to increase your odds of getting them than by breeding a tri to a solid harlie.
Clear as mud?
Within all the instructions of a rabbit's genetic code, there are a bunch of genes that influence coat color, one way or another. For every trait, a rabbit has two genes that control it, one that came from the mother, one that came from the father. If the rabbit inherits the same form of a gene from both the mother and the father, we say it is homozygous. If the two forms are not the same, the rabbit is heterozygous for that trait.
A dominant gene is one that, if a rabbit inherits it, you will see its effects. It can't hide. A recessive gene "takes a back seat" to a dominant; to see it, you usually need the animal to have inherited the recessive form from both of its parents - in other words, to be homozygous recessive. Most of the time, you can't tell if an animal is homozygous or heterozygous when the dominant form is present, because it looks exactly the same. There are exceptions, and rabbit coat color has several remarkably different examples of this. One is the broken gene.
In a discussion of rabbit coat color, the broken gene is symbolized En. This is because it was first identified in the English Spot breed. Animals with the broken gene generally have white on their feet, their bellies and chests are (at least mostly) white, and there is usually some white on the face and tail. There are a whole slew of modifier genes that fine tune the exact appearance of any particular rabbit with the broken gene. People with breeds like English Spots and Checkered Giants are very picky about just which form the modifiers must be, and want the markings to look just so. Most other breeds that employ the broken gene are not as selective, allowing a much greater range of expression in their brokens. The two kits (broken red and tricolor) that you posted pics of appear to be quite typical, acceptable MR brokens.
There appear to be only two possibilities at the En locus (the place where the broken gene happens), En (broken) and en (not broken [solid]). En is dominant, so an animal with one copy of each (heterozygous) will be a broken. A solid is clearly enen, homozygous recessive. Curiously, there is a marked difference between the appearance of a heterozygous broken, and one that is homozygous. The EnEn rabbit has very little color on it at all. There usually is some color on the ears, some around the eyes, and little or none on the nose. There is very little color on the body, as well. These animals are often called "Charlies" (I've heard it is because the small mark that they may have on the nose reminded someone of a Charlie Chaplin moustache). Because the Charlie has only the dominant En form, all of its offspring will inherit the broken gene from it, and be brokens.
The harlequin gene (eh) is found in the E series. There are a couple of other genes in this series that are dominant to it, but only one (e) that is recessive. e is the "non-extension" gene, the one that gives you red and tort. The harlie gene is kind of weird, in some places it acts like the non-extension gene, and removes black from the hair shaft, and in other places it acts like the self gene, flooding black all over the hair shaft. Like the broken gene, the harlie gene sets the pattern, there are other genes that modify the way the pattern gets expressed. I breed Harlequins (the breed) and I have seen even pedigreed, homozygous Harlies with barely more pattern than the black streak you describe your buck as having. He sounds like a harlequin to me.
Tricolors, of course, are nothing at all but broken harlequins. There are several breeds that recognise tricolor for the purpose of showing, but not its solid counterpart, harlequin (I'm sure it makes sense to someone). Other than it being unshowable, there is no reason to exclude a harlie from a tricolor breeding program. If you are trying to avoid producing the nearly all-white, EnEn Charlies, you would breed solid to broken. Since the "good" broken is Enen, some of the offspring are bound to be solids. If you are trying to breed showable tri's, the best way to increase your odds of getting them than by breeding a tri to a solid harlie.
Clear as mud?