New member interested in rabbit genetics!

If possible, my goals are to get more meat on them, get faster growth rates, breed for red and maybe blue, and generally breed to improve my herd.

I think those dark kits could very well be steel; I can't think of anything else they would be. And although it's really hard to be sure what I'm looking at due to the vagaries of lighting in photos, it seems to me that your black doe has some steeling on her as well. If you zoom on that section, it appears that she has light bands near the tips of the hairs.

This patch of what seems like steel actually looks kind of like what I've seen in supersteels, but if she was <E(S)E(S)>, all of her kits would have inherited a copy of the steel allele, and I don't think you could have gotten those harlequins. I've never seen how steel <E(S)> interacts with harlequin <e(j)> but I suppose that's a possibility.

In fact I think that must be it, because...you know your black doe at least carries harlequin <e(j)> since she made harlequin babies (the red buck can't carry harlequin since he's <ee>). And the red buck can't carry steel, either, for the same reason, so again, it must be the doe. So... I think you've just shown us what <E(S)e(j)> looks like!

I have also read somewhere that when a rabbit has both steel-extension <E(S)> and non-extension <e>, it may have slightly reduced steeling, so maybe that's what's going on in the babies, with their very light steeling.

Alaska Satin said:

I think those dark kits could very well be steel; I can't think of anything else they would be. And although it's really hard to be sure what I'm looking at due to the vagaries of lighting in photos, it seems to me that your black doe has some steeling on her as well. If you zoom on that section, it appears that she has white bands near the tips of the hairs.
View attachment 44312
This patch of what seems like steel actually looks kind of like what I've seen in supersteels, but if she was <E(S)E(S)>, all of her kits would have inherited a copy of the steel allele, and I don't think you could have gotten those harlequins. I've never seen how steel <E(S)> interacts with harlequin <e(j)> but I suppose that's a possibility.

In fact I think that must be it, because...you know your black doe at least carries harlequin <e(j)> since she made harlequin babies (the red buck can't carry harlequin since he's <ee>). And the red buck can't carry steel, either, for the same reason, so again, it must be the doe. So... I think you've just shown us what <E(S)e(j)> looks like!

I have also read somewhere that when a rabbit has both steel-extension <E(S)> and non-extension <e>, it may have slightly reduced steeling, so maybe that's what's going on in the babies, with their very light steeling.

Click to expand...

I didn’t know that the black in a red x black outcross had to carry the gene for steel. That’s not what all the other posts I looked at before this said, so now I’m very relieved. I thought the red and black genes got together to make the steel gene. I’m glad I could inadvertently show you something new
Now I have another question. If I breed a harlequin back to one of my reds, will I get all harlequins, or a mix of both? I would think all because of the dominant lettering in the gene coding, but what do I know? That’s why I’m here lol

BlueMeadow said:

I didn’t know that the black in a red x black outcross had to carry the gene for steel. That’s not what all the other posts I looked at before this said, so now I’m very relieved. I thought the red and black genes got together to make the steel gene. I’m glad I could inadvertently show you something new

Click to expand...

As far as I know, a red rabbit cannot hide any other allele at the E locus, because to be red, the rabbit must be homozygous for non-extension, i.e. <ee>. That means steel, harlequin, full-color <E> or dominant black <E(D)> cannot be there. The E locus is known for partial dominance relationships among the alleles there, though, as well as changing effects depending on other loci, especially the A series, so I always hesitate to write too stridently about E alleles.

It might be helpful to think about a steel phenotype as being a combination of alleles at two loci - A and E - rather than coming from a "steel gene." Steel <E(S)> is a pattern allele that changes the way colors are arranged on each hair shaft. To look like a steel, the rabbit must have both agouti <A_> and steel <E(S)> alleles, because the agouti pattern gives the steel something to work on. So you were right - in a manner of speaking, genes from a red and a black get together to make steel...as long as the black has that steel allele (a red always has at least one agouti allele). I've discovered that even in purebred NZ blacks and whites, many carry steel (and also chinchilla <c(chd)>), but you'd never know it as long at they're bred self black x self black or white x white.

When you have something other than agouti <A_> at the A locus, the <E(S)> will have a different or no expression. A dominant tan <a(t)_> will make a steeled otter (up here we call them "tweeners") which has reduced otter trim made up of steel ticking. A homozygous self <aa>, in which the banding and trim patterns are suppressed, leaves the steel pattern alleles nowhere to express themselves; thus a steel can lurk in selfs for a long time, until you happen to breed one of them with a tan or an agouti. So, when you breed a red with a black that carries the steel allele, some kits get the <A_> from the red, and the <E(S)> from the black (which, because it is a self, can "be steel" without looking like a steel), and voila, you have surprise steels.

Another thing that can happen in black rabbits is that even in an agouti, two copies of the steel allele <E(S)E(S)>, known as "supersteel," can also result in the rabbit looking like a self black (sometimes with irregular patches of faint ticking which can look a bit like stray white hairs). If that's the case, breeding that black with a red should result in most or all steel kits, because every kit gets a copy of steel, and at least some will get the agouti that unlocks the expression of steel. (I'm leaving out the complication of C series alleles like REW <c> that will override everything else.) You will not get any reds at all (though all kits will carry a copy of <e>), and you won't get any supersteels for the same reason. So if you get solid blacks as well as steels, you'll know that both parents carry a recessive <a> and the black kits are <aaB_C_D_E(S)e>, called self steels.

One thing I've found to be extremely helpful in identifying some of the trickier varieties is a suggestion made by @reh. That is to pull single guard hairs for closer examination. If the rabbit is silvered or has simply stray white hairs, the hairs will be entirely white, like this:

But if the rabbit has steel expression, the hairs will be banded like an agouti, only all the color is pushed up to the tip, like this:

Now I have another question. If I breed a harlequin back to one of my reds, will I get all harlequins, or a mix of both? I would think all because of the dominant lettering in the gene coding, but what do I know? That’s why I’m here lol

Click to expand...

Since you know your reds must be <ee>, every one of their kits will carry an <e>. Thus their harlequin kits will be <e(j)e>, so statistically you'll get about half of each when you breed them back to the red. You can use a Punnet Square to visualize that, for example with the red sire on the top row and the harlequin offspring on the left column:

The caveat (there always seems to be a caveat ) is that the chart above assumes all the kits get an agouti <A_>. If they end up with paired self alleles <aa>, which they have at least some chance of doing, you may also see torted harlequins and/or torts.
I've attached some worksheets that I made for using in my classes. While a lot of it may be stuff you already know, the list of gene series on the Genetics II page might be helpful to organize what you know about the different alleles. It's a lot to juggle mentally!