Rex acts as recessive?

Discussions and questions about genetics, what variety a rat is and such like.
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Orchamo
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Rex acts as recessive?

Post by Orchamo » Sun Oct 04, 2015 12:11 am

Hello, i had somthing a bit wierd going on and i really wanted to understand what is the explenation to it.
I bred an albino hooded rat to a dumbo black rat(white sucks and white belly mark). All the pups came out as expected, except one, he was bald you could see that he was hooded, but really had no hair what so ever, after a while he got a whisker on his face, and body, and again, no hairs at all. Now again he got some hairs but not alot on all of his body. Thats sound like a double rex to me.. but the parents are not rex, not even very weak onse, normal fur since they were babies. I know the father and the mother has rex brothers... the moms sister is a rex and she had rex babies so like the ususal, dominant trait. Can anyone explain where did it came from or why did it happen? Rex acting different? New wierd gene? This couple had another clutch with 5 babies like that. And i know there isnt a true hairless in those families.
Thank you for your time :) i will upload photos in a few hours :)

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cyber ratty
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Re: Rex acts as recessive?

Post by cyber ratty » Sun Oct 04, 2015 10:05 am

There is a recessive rex gene, it's different from dominant rex.

However, some recessive genes can lurk in lines for many generations without showing up, so there could be a possibility of it being hairless.

Orchamo
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Re: Rex acts as recessive?

Post by Orchamo » Sun Oct 04, 2015 11:13 am

This is the family
mother--
Image

Father--
Image

Babies--
Image

Grown offspring--
Image

Ok interesting.. for some reason i dont think hairless is a pssability. But about the recessive rex... how does it work? I mean as far as i know a recessive trait must have 2 genes to effect, which in rex mean double rex? Because of the two genes? And that means that there is no single gene morph? I cant get the curly hairs? Right?
And thank you :)

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cyber ratty
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Re: Rex acts as recessive?

Post by cyber ratty » Sun Oct 04, 2015 1:35 pm

The recessive rex gene is a completely different gene from the dominant rex gene, and is at a different locus. It works like any other recessive gene, so yes, you need two copies for the rat to then express the recessive rex coat.

So (at the risk of confusing you further!), it is possible for a rat to be expressing recessive rex, and also be dominant rex or double rex. I'm not sure of the notation used for the recessive rex gene, but let's call it rr. Then a recessive rex rat is rr rr, a dominant rex rat is Re, and a double rex is Re Re, so you could have a rat being both which would be rr rr Re or rr rr Re Re.

ETA - I've not had any experience of recessive rex coats myself, but the type that appears in the UK is far more hairy that the one you have. Maybe there are other coat genes affecting it - is either parent satin?

Orchamo
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Re: Rex acts as recessive?

Post by Orchamo » Sun Oct 04, 2015 4:36 pm

Thank you for your answer :)
The part of how the genetics work i understand but i didnt quite understood, the coat of a recessive rex when expressed, is like a hairy double rex?
And its just hard for me to belive there is a recessive rex involved, i dont belive the breeders i bought the rats from(two different onse) have come across those genes. In my country rats are not popular as well..
There is no satin involved,but the father does have extremely soft fur. I dont know this trait as a gene, regular fur, not curly, not longer, just softer.
Thank you for responding and i think i will keep the babies, and breed them to understand how this gene acts.

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Stovokor
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Re: Rex acts as recessive?

Post by Stovokor » Sun Oct 04, 2015 8:28 pm

Recessive rex looks exactly the same as regular rex, but with longer guard hairs as it's less prone to coat breakage.

Orchamo
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Re: Rex acts as recessive?

Post by Orchamo » Sun Oct 04, 2015 8:31 pm

I couldn't find a picture of a recessive rex so thank you for the description :)


Orchamo
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Re: Rex acts as recessive?

Post by Orchamo » Sun Oct 04, 2015 9:36 pm

They are cute :) the "recessive rex" i have lost all its hairs and grew them back all over the body, except on the back of the head and few more places. He is more like the rex and the recessive rex together i guess, but non of his brothers or in the litter after are rex... thank you for the photos! :)

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Stovokor
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Re: Rex acts as recessive?

Post by Stovokor » Sun Oct 04, 2015 9:38 pm

You probably have hairless then.

Orchamo
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Re: Rex acts as recessive?

Post by Orchamo » Tue Oct 06, 2015 7:52 am

So i guess ill know it in a few months?

Tenmashi
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Re: Rex acts as recessive?

Post by Tenmashi » Tue Oct 06, 2015 1:55 pm

Looks like some type of fuzz. Apparently there are several different fuzz/hairless genes around with different degrees of baldness.
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