Finding the hidden steel gene in rabbits

[Higher Ground Rabbitry]

I know my New Zealand blue rabbits carry the rather baffling steel gene. Personally I'd rather have steel than chestnut, but it can mess with the blues and blacks, so we're trying to breed it out. The problem is verifying whether or not a rabbit is carrying it! I have been planning to breed a fawn rabbit (a dilute that cannot hide steel) with a black rabbit (blue if I can get it). I figured a true black would produce half chestnut, half black (assuming my fawn carried self), while a self steel would produce maybe 1/4 chestnuts,about half apparently black, and about 1/4 clearly steel, so I should know for sure if the steel gene was there.

But I was truly, utterly flummoxed to read about someone who crossed a chestnut doe with a red buck and got 3 REW, 3 chestnuts, and 3 gold tipped steels!! When I asked, she said she thought the steel was coming from her chestnut doe, who had a blue mother and a REW father. I know white often hides steel, but how could a chestnut hide it?!?

I would LOVE to figure this out before breeding a whole new line just to find out the steel gene snuck in anyway. I was hoping someone, maybe the Bunny Lady, would have some thoughts on this aggravating gene!

 

[sourland]

@Bunnylady , hopefully this will catch her attention. Have you tried starting a conversation with her ?

 

[Higher Ground Rabbitry]

I'm afraid I have a hard time figuring out which buttons to push. Thanks for the help!

 

[Bunnylady]

Welcome to the forum!Glad you joined us.

Workin' on it, sour, workin' on it . . . .

As you know, a chestnut crossed to a red shouldn't be able to produce steel. In the E series, the gene for steel (Es) is dominant to both the E of the chestnut and the e of the red. If the chestnut had a steel gene, it would be steel, and Ese should be a black (or black with just a little bit of ticking), not a red. But there they are.

I'm going to assume that this isn't a case where the doe was bred by another buck besides the one the owner thinks sired the litter (that would be the easy answer, of course!).

So what I'm left with is, how could either a red or a chestnut actually be a steel? And the only possible wild card that I can think of is the wide-band gene.

Red NZ's have two copies of non-extension; that pushes the black on an agouti-patterned rabbit's hairs to just the tip of the hair. Wide band (w) acts in a similar manner, plus putting red/yellow pigment in places where it doesn't usually appear, like on the belly. With both non-extension and wide-band, you get all of the black off the body hairs, and (usually) a colored belly, which is how red NZ's almost look like self-colored animals.

Steel works in the opposite way; it allows the black to come further down from the tip of the hair, covering more of the lighter middle band. Steels often have darker bellies, etc, too.

I've had a little bit of experience with the steel gene, but I don't remember ever owning rabbits with wide-band. I can't help but wonder - what happens when steel and wide-band go head-to-head? Might a wide-band steel resemble a chestnut? I don't know.

The problem with this, of course, is that wide band is recessive; to see the results of wide band, the rabbit has to be homozygous for it. A red buck should be homozygous for wide band too, so all of the babies should be homozygous as well. A wide band chestnut is noticeably lighter than a normal chestnut, so it's possible to have agouti-patterned animals of two different shades, but the darker ones should still look like the doe, which has been called a chestnut. If the buck isn't a good, wide band red, I suppose that could account for it . . . . gotta say, it's intriguing.

Y'know, when I took genetics in college all those years ago, we joked that when Gregor Mendel was working out his theories with his peas and other plants, anything that didn't work out the way he thought it should went into the compost heap on the other side of the garden wall. I suspect this doe would be one he'd put over the garden wall (or in the stewpot, more likely). Problem solved!

 

[Higher Ground Rabbitry]

Thanks for sharing my frustration. Usually if I employ the words "non-extension" people's eyes glaze over!

I'll try not to overload you with information, unless you just want me to. Our herd of NZs started with one red buck and one "blue" doe. They produced some reds and some like this. (Sorry about the molting.)

So, my doe is dd Ese, and this buck is Dd Ese. We bred him back to the blue doe, and they've produced steel, black, blue steel, blue, REW, red, and fawn. I would have thought if either one was NOT wideband, the reds they produce should look noticeably different from the original red buck, but they don't. So, I suspect we have a wideband steel here. Although I suppose it's possible our reds rely on rufus modifiers, but they're a pretty deep red.

 

[Higher Ground Rabbitry]

I don't know why I didn't think about our Flemish cross before starting this thread. We had a black Flemish doe that we bred to the same wideband steel NZ buck. She only raised 6 kits in two litters. Her first litter had a chestnut and two steels (if I remember right). Her second litter had two mostly black with some steeling and one I called Oddball.

Oddball looked a lot like a chestnut - but with no white belly! I finally decided he was just heavily steeled - but I have no idea why that would be.

 

[Bunnylady]

Please excuse my rather sporadic attention; with a Category 5 hurricane in the Caribbean and a new track forecast just skimming up the eastern side of Florida, I'm a bit distracted. Having lived here on the coast for over 30 years, I've experienced far too many storms to turn my back on this beast!

Flemish Giants don't show in Chestnut; their showable equivalent is a color called Sandy (which as near as I can tell is a wide-band version of Chestnut).

Oddball is certainly an interesting color. Of course, that's a baby coat in that picture, and baby coats can differ from the adult coat by a bit. I'd be curious to know how a coat like that would finish, because that's pretty much what I'd expect a wide-band steel to look like - color on the belly more like a steel, but with the extra black of steel reduced because of the extra-wide light colored band of the wide-band.

Just to be sure we are on the same page, this is a normal steel (EsE):

It looks like an unusually dark chestnut, except that it most likely also has a dark belly.

Steel is a weird gene. If you combine it with any other gene in the E series besides normal extension (E), it will look different. And it only shows up on agouti patterned rabbits.

This guy might look like a self patterned rabbit (aa) that is showing ticking because it has steel, but he isn't. He's an agouti patterned rabbit (A_) that almost looks like a self because he has steel. I have a couple of NZ/Harlequin cross does that I know to a certainty are not self (aa), but are jet black, no ticking whatsoever, because they are Esej (I don't currently have pictures of them, and since it is pouring outside, sorry, I don't feel like slogging out to get pics. You'll just have to trust me on this one). There is also something that some people call a "super steel" - EsEs, which also looks exactly like a self. [Incidentally, those blacks and blues that you got when you bred Junior (I assume that's his name? That's what the tag said) back to his mother could be super steels, or they could be selfs.]

Everything I have ever heard and read has said that steel does not express on self; a rabbit has to have the agouti pattern gene for you to be able to see steel. Your blue doe may be a true self (aa) with steel, and that is why she doesn't show it. You could breed self-patterned steels together forever, and never know the steel gene was there. A person could go along, happily breeding black super steels together and none the wiser, and then one day buy a black rabbit from another bloodline that was a self, breed it, and - "what the heck??? where did that come from??"

 

[Higher Ground Rabbitry]

No need to apologize for having good priorities. . I'm just excited to have someone to talk to who doesn't think the "self" rabbit is the one hogging all the food! . If you're plain not interested, I won't be offended at all.

I'm kinda obsessing over this right now because I'm trying to figure out what it will take to be confident whether a particular rabbit carries steel or not. That way the random ticking won't keep showing up in my herd, and I won't worry about accidentally selling this problem to someone else! (Ok, so maybe it's also because I'm a tad obsessive. I hate feeling defeated by this gene!)

I'd like to show you Oddball's adult coat, but he fulfilled his destiny as a meat rabbit. And with only three kits per litter, his mom soon followed, so we won't be recreating that one.

Do you have any experience with how consistent the gene is? In my little world, the same genotype is supposed to look at least similar on each rabbit, but I'm afraid this gene has some unknown factors that complicates things. For example, I'm beginning to suspect that my blue doe is A_Ese and shows NO ticking, while my buck Junior (yes, that's his name) is also A_Ese and has always shown some very obvious ticking. I really don't want to accept that I must test breed each and every rabbit, but I'm afraid I'll have to. (Then I'll have to figure out which crosses will work as a test!)

 

[Bunnylady]

I imagine there's some set of modifiers that determines just how a steel gets expressed, but I don't know what they are. As I said, I have a couple of solid black does that I know are Esej. All of the offspring of that particular pairing were born solid black, some developed a little bit of ticking as they grew older (looking almost like a Silver Fox), some remained pure black. Most of the rabbits that I believe to be Ese have looked like this:

Evidently, though, they can be solid colored like a self, as well.

If you are working with blue NZ's, this may be something else that may pop up to really drive you crazy:

As near as I can tell, this rabbit is a self chin - aacchd_(neither the rabbit nor the picture are mine). It had blues in its background. I remember a conversation a few years ago with a couple of people who were breeding blue NZ's; one was getting rabbits that were two distinctly different shades of blue, and was wondering which one was the "correct" shade. I have a feeling the lighter ones were blue self chins. Chin takes a little bit of the black pigment out, as well as the yellow/red, so it would make sense that the dilute would be a bit lighter than the dilute of a normal full-color black. Don't know why chin would be running around in NZ's, but apparently it is, at least in some lines of blues.

 

[Higher Ground Rabbitry]

I appreciate all the tips. If I accept that my "blue" doe is A_ddEse, the riddles start to get easier... but the breeding gets harder! I knew I didn't have a full extension gene in my barn. Now I may not have a self gene, either!! Apparently I'll be asking for a bunny for Christmas...

A friend of mine said some of her rabbits had blue eyes, so she thought they already had steel and weren't worried about buying our buck that carried it. I never read anything about steel affecting eye color, but I did hear self chins sometimes have blue eyes. I think I'll stick to her red line. I don't need chinchilla genes!

If there's anything else you're curious about, I'd be happy to add more details. If not, I'll leave you alone now. Thanks again, and I hope hurricane season treats you decently!