Lethal factor

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Correct me if I'm wrong but is it true that the lethal factor is in the velvet gene itself? So it doesn't necessarily have to be black to black but could happen when breeding any two chins with the velvet gene.

ex brown velvet x white TOV etc../.

In short, yes, that's correct.

There are lethal factors associated with the black gene and the white gene - they are not the same lethal factor so a black can be bred to a white with no statistical loss of offspring, but not to another black or black hybrid. The lethal factor still applies in black hybrids and white hybrids (such as pink white to pink white, as this post was originally about). It does not matter what other colors are present - if there are two black mutant alleles on the black gene, or two white alleles on the white gene, the kit will abort.
 
Black is a TOV Standard for all intents and purposes. They are, however, referred to as "black" and not TOV. Black and ebony are two separate colors.
 
I have to agree with peggy on this one... Many ranchers have bred, and do breed black velvet x black velvet, and have produced some darn nice black velvets...Yet many of us support these ranchers...One of my favorite blacks has a black x black breeding in her line.. This line had produced and shown very well for the breeder...
 
Sorry, Black is the term used for black velvets.

Peggy I know there are ecxpetions to every rule. I am thinking more along the breeders who do it with no reason other than they can or just to produce more mutations..like peopel who breed sapphire to sapphire. I was thinking more of Backyard breeders than the Ranchers.
 
I didn't know there was actually two lethal alleles. Is that rare in one species? Hhhmmmm...I wonder.

So, if reabsorbing a fetus is not detrimental--is there actually an issue with breeding parents who might have homozygous mutant allele babies? Or is there a risk of actual abortion too?
 
I didn't know there was actually two lethal alleles. Is that rare in one species? Hhhmmmm...I wonder.

No, it's not rare. There are many, many known examples of lethal factors, and most likely many more than that that we don't know about.

So, if reabsorbing a fetus is not detrimental--is there actually an issue with breeding parents who might have homozygous mutant allele babies? Or is there a risk of actual abortion too?

Whether or not it is detrimental in the long term is not known. I'm not sure what you mean by actual abortion - the embryo does abort in the biological definition of the word: cessation of development/growth. If you mean abortion in the sense of an expelled fetus, no, that doesn't happen.

The issue, in my opinion, is quality. I am not as against black x black pairings (when done by those who know what they're doing, and not by BYBs solely to produce fewer standards) because blacks are the overall strongest mutation, almost on par with standards. If the parents compliment each other, there's no reason why they couldn't have offspring that are an improvement on them. However, I personally still have an issue with putting a female in a position to reabsorb multiple kits over her lifetime, and as you can still get quality black offspring breeding a black to a pure standard I just feel that that's a safer breeding practice for the female.

White x white pairings, however, I doubt any offspring would be an improvement. The major faults in whites tend to be the same: cottony fur and yellow cast. Doubling that with another white parent would just produce weaker, yellower fur. Show me a white that compliments another white better than every pure standard out there and I will change my mind on this.
 
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When it comes to animals I have always tried to follow the rules others have set fourth, I'm a firm believer in learning from others mistakes. Some experimentation is expected but should only be performed by those who trolley know what they are doing
 
I agree. If the effects of reabsorbing a fetus either once or multiple times is not known in chins then it probably should not be attempted. There may be an argument for doing some sort of scientific experiment if there is no other way to reasonably find out those effects.

Mish--I did not know that, that's interesting.
 
Excuse me for coming in on after reading these three pages.

Is there a website about what the Lethal Factor is? I'm just hearing this for the first time, and also why people say you should not breed white x white, black x black...

I'm just wondering because Neve's breeder was a little hillbilly-ish, no line and neve had no documentation whatso ever...

In general i'd just like to educated myself on these terms I dont know.
 
There's an FAQ on it, though it's not a scientific in depth article, more reiterating what Mish said http://www.chins-n-hedgies.com/forums/showthread.php?t=22

I've done a quick search on the internet, and there really isn't any documentation that I've found. I'll continue to try and find information on this. I would imagine Alice Klein addressed this in her book about chinchillas, Basic Genetics and History of Mutation Chinchillas. I don't have the book myself, but maybe someone who does can fill us in.
 
I agree. If the effects of reabsorbing a fetus either once or multiple times is not known in chins then it probably should not be attempted. There may be an argument for doing some sort of scientific experiment if there is no other way to reasonably find out those effects.

Eh, as I said in my first post, I don't think this study would be ethical. You would be intentionally doing something for no other reason than to see if it harms an animal.
 
Rob, here is an article that explains lethal genes: http://www.nature.com/scitable/topicpage/mendelian-ratios-and-lethal-genes-557

Most of the examples they give are of human lethal genes, but the beginning of the article about yellow mice is similar to what we observe in chinchillas... and how we came to realize that white and black are lethal. Why these genes are lethal, no one knows, but I for one would love to find out.
 
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