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Calico BNs?

Posted: 20 Jan 2009, 19:34
by Kets
I'm just wondering, but what species of BN are Calicos? I've heard of them being a color morph of the common BN. If so, how exactly do the genetics work out?

Re: Calico BNs?

Posted: 20 Jan 2009, 19:38
by MatsP
Well, technically "Calico" is a heredetary genetic defect, so it can happen to nearly all fishes (Koi carp and Goldfish often have spots/blotches caused by a similar genetic defect). But the commonly available, the only one KNOWN to us, calico form is .

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Mats

Re: Calico BNs?

Posted: 20 Jan 2009, 21:11
by Kets
MatsP wrote:Well, technically "Calico" is a heredetary genetic defect, so it can happen to nearly all fishes (Koi carp and Goldfish often have spots/blotches caused by a similar genetic defect). But the commonly available, the only one KNOWN to us, calico form is .

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Mats
What Kind of fish do you get if you cross it with an Albino BN or a Brown BN?

Re: Calico BNs?

Posted: 20 Jan 2009, 23:35
by MatsP
A brown one, unless one of it's parent's happen to be albino, that is. Cross the children again, and you get a mix of brown, calico and albino, most likely 50%, 25% and 25% [although this is a statistical average, and it may take quite a few batches of fry before it matches the average, just like if you toss a coin, you may get two or three heads in a row, but if you toss many enough times, in the end you get 50:50 split between heads and tails (and the odd one standing on the side :)].

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Mats

Re: Calico BNs?

Posted: 20 Jan 2009, 23:41
by Kets
Thanks for the explanation, but I'm confused on why you can get Albinos from Calicos? Are the two color morphs related?

Re: Calico BNs?

Posted: 21 Jan 2009, 00:05
by MatsP
Kets wrote:Thanks for the explanation, but I'm confused on why you can get Albinos from Calicos? Are the two color morphs related?
They are not directly related.

To put it in a different way: It is different genetic "mishaps" that cause the colour defects, albino and calico, so you can combine them in different ways. But the first generation from such a mix will be brown ones, but latent carriers of albinism and calico, so if you mix the genes back again, one half will carry one albino and one normal, one calico and one normal, a quarter of the fry will have two albino genes, and a quarter of the fry will have two calico genes. Since you need a "matched pair" to get albino or calico, the ones that have one calico and one normal gene, or one albino and one normal gene will be brown, because the "normal" colouration is what's called dominant.

Much more text and some pretty pictures here - not about bristlenoses, but it shows how you work out "what you get if you mix...":
http://en.wikipedia.org/wiki/Mendelian_inheritance

Searching for Mendelian genetics will give you MANY pages of web-content that may or may not explain this better than I have.

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Mats

Re: Calico BNs?

Posted: 21 Jan 2009, 02:26
by Kets
Ah, I get it now. But what would you get if you get one albino gene and one calico gene?

Re: Calico BNs?

Posted: 21 Jan 2009, 09:56
by MatsP
Kets wrote:Ah, I get it now. But what would you get if you get one albino gene and one calico gene?
They are not in the same place in the DNA chain - so you can't "combine" calico with albino - you get a brown fish if you have one of each, and if you have two albino genes and two calico genes, then you get an albino calico [which will look like a normal albino, since you won't see the lack of colour in some parts of the body, since the rest of the body is also completely missing colour].

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Mats

Re: Calico BNs?

Posted: 21 Jan 2009, 21:13
by Kets
Thanks!