# broken red new zealand



## jdubya (Oct 26, 2013)

can you breed for broken red new zealands using a red and a white?


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## Bunnylady (Oct 26, 2013)

Broken is a particular gene. Either a rabbit has it or it doesn't; you can't "make" it. Broken is also a dominant gene, which means that if a rabbit has it, you'll see it. A Ruby-eyed White _might_ have a broken gene and you couldn't see it, but most REW's don't have the broken gene. 

Since a lot of NZW's carry Steel, the most likely result of breeding a NZW with a NZR is black or Steel. If you want to breed brokens, you have start with a rabbit that has the broken gene.


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## jdubya (Oct 26, 2013)

thanks bunnylady.  does that mean if I have a heterozygous broken coat crossed with a white mate, ill get 25% broken offspring?


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## Bunnylady (Oct 27, 2013)

The best way I can think of to put this is to think of the rabbit's genetics as a string of beads. A whole bunch of those beads affect the coat color; it is the influence of all of them together that determines what color the rabbit is. If we are talking beads, think of it this way - the beads are in a certain pattern (let's say by color), though they may be different shapes. So in the first position, let's say we have a red bead. That bead might be round, oval, or egg-shaped, but it is always red, and this is the only place a red bead can be. The next bead is blue. It might be square, or octagonal, but it is always blue. Only the blue beads are squares or octagons, and only blue beads can be in the second position. There is a yellow position, an orange position, a green position, etc; each of those positions can only have a bead of that color. 

REW happens at the C locus. It is the most recessive of the C series, so for a rabbit to be a Ruby-eyed White, it must have 2 copies of the REW gene (cc). Since it only has REW genes at that position, all of its offspring will get a REW gene from it. Just looking at a REW, you can't tell whether it has a broken gene or not. (I once had a REW Holland Lop doe that inherited a broken gene from her father. Because she gave birth to brokens when bred to a solid, colored buck, I knew she had it, but of course, you couldn't see it. I jokingly referred to her as a "broken REW.") 

Broken happens at the En locus (En for "English," since this gene was first identified in the most finely detailed of the broken patterned rabbits, the English Spot). There are only 2 possibilities at the En locus, broken (En) and not broken (i.e. "solid", en). Broken is one of those genes that has a cumulative effect, so  rabbits that have 2 copies of the broken gene have a whole lot of white and only a little bit of color - we call them "Charlies." A "good" broken would be heterozygous, meaning that it has one copy of the broken gene, and one of the not broken gene. 

In your hypothetical cross between a broken and a REW, it's hard to say exactly how the breakdown of color would occur. Theoretically, the broken is giving the broken gene to half of its offspring, though in a sample group as small as one litter or even the lifetime production of a single rabbit, the results could be widely skewed. Unless you have had broken offspring from the REW, you have no clue whether the REW may have a broken gene. You know the broken has one broken and one not broken gene, and you know it has at least one copy of something other than the REW gene at the C locus (we'll assume it's the full-color gene C), but you don't know, the other gene at the C locus might be a REW gene. The only way you'll see REW's from this cross would be if the broken was carrying a REW gene, but if you did get any REW's, you couldn't be sure whether they got the broken gene, too. 

Clear as mud?


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## jdubya (Oct 28, 2013)

since a Charlie has 2 broken genes, does that mean it is homozygous for a broken coat?  will a red Charlie bred to a solid red produce all red charlies?


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## treeclimber233 (Oct 28, 2013)

A red Charlie bred to a Solid Red will produce all broken reds.


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## Bunnylady (Oct 28, 2013)

jdubya said:
			
		

> since a Charlie has 2 broken genes, does that mean it is homozygous for a broken coat?  will a red Charlie bred to a solid red produce all red charlies?


A Charlie is homozygous for Broken, yes. If you cross a Charlie to a Solid, all of the offspring will be Brokens. Sometimes, you may come across a mostly white rabbit that you might think is a Charlie, that is actually heterozygous. If you get solids from what appears to be a Charlie, you know it's not really a Charlie, it just looks like one.


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## jdubya (Oct 28, 2013)

it all makes sense now. thanks treeclimber and bunnylady.


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