I love the fact that only females can be Calicos and Torties (and those that appear to be male are actually sterile hermaphrodites)... I didn't know that until our vet told us that when we brought in our 6 week old baby Calicos,
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Calicos and Torties
- Thread starter summeroflov
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Most sources say that about 1 in 3000 torties/calicos are male. There is apparently another way that males can be tortie, as some well-known purebred studs are torties, obviously not sterile! Chimerism, I think. And most male calicos are not hermaphrodites, exactly; if you want to compare it to humans, it would be like Kleinfelter's Syndrome---XXY chromosomes. But, yeah, it's cool that most are female, it makes it so easy to tell 
. And, for more interesting trivia, about 75% of orange tabbies are male. Cat genetics are so interesting 
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. And, for more interesting trivia, about 75% of orange tabbies are male. Cat genetics are so interesting .
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I agree the sex-linked Red (Orange) gene in cats is one of the more fascinating things in cat color genetics!
Male Torties are not usually exactly hermaphrodites ( with both male and female sex organs) but of the very small percent of male torties or calicos, most of them have those colors because they have an extra X chromosome, and that does usually make them sterile.
There are also some other ways that a male can be a tortie or calico, and not be sterile. So there are some fertile male torties - they are just even more rare than male torties in general!
Male Torties are not usually exactly hermaphrodites ( with both male and female sex organs) but of the very small percent of male torties or calicos, most of them have those colors because they have an extra X chromosome, and that does usually make them sterile.
There are also some other ways that a male can be a tortie or calico, and not be sterile. So there are some fertile male torties - they are just even more rare than male torties in general!
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Ah okay, thanks for that info! I was going off what the vet had said, but I guess there's probably not a true human equivalent. Could be chimerism... I've always found that concept (in humans) interesting...
It is a similar chromosomal abnormality to what can cause a hermaphrodite with ambiguous sex organs or both kinds of sex organs.
So it did make sense for the vet to make that analogy, I just wanted to say it does not necessarily cause some definite physical abnormality that can be seen. an XXY male has an extra X like a female. but his body ( except for the color) might look like a normal male.
Re chimerism -- yes you are right . That is something that can cause a male cat to be a tortie -- when 2 fertilized eggs fuse to become one embryo . and one of the fertilized eggs had the genetic code for red-based color and the other had the code for 'not red' ( which means it defaults to black-based color).... so the eventual kitten can be a male tortie with XY/XY .
I think in recent years it is being recognized that this may be just as common, or even more common as a cause of tortie males than the X chromosomal abnormality.
( Of course whichever the more common cause for it, tortie males are definitely rare. But I think it's been learned that more of them are fertile than had been previously thought.
Here is an article from the messybeast site about this http://www.messybeast.com/mosaicism6.htm
So it did make sense for the vet to make that analogy, I just wanted to say it does not necessarily cause some definite physical abnormality that can be seen. an XXY male has an extra X like a female. but his body ( except for the color) might look like a normal male.
Re chimerism -- yes you are right . That is something that can cause a male cat to be a tortie -- when 2 fertilized eggs fuse to become one embryo . and one of the fertilized eggs had the genetic code for red-based color and the other had the code for 'not red' ( which means it defaults to black-based color).... so the eventual kitten can be a male tortie with XY/XY .
I think in recent years it is being recognized that this may be just as common, or even more common as a cause of tortie males than the X chromosomal abnormality.
( Of course whichever the more common cause for it, tortie males are definitely rare. But I think it's been learned that more of them are fertile than had been previously thought.
Here is an article from the messybeast site about this http://www.messybeast.com/mosaicism6.htm
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Chimera males can definitely be fertile; there's nothing particularly stopping them from it. XXY males, not so much, but it can happen.
Both should be neutered anyway; they will have the hormones that push them to spray and yowl and generally do tomcat things that force out their friendly kitten personality and make them go and fight for females. One tomcat can account for a bushel of kittens, and since there's already too many kittens, it's best to get them fixed.
Both should be neutered anyway; they will have the hormones that push them to spray and yowl and generally do tomcat things that force out their friendly kitten personality and make them go and fight for females. One tomcat can account for a bushel of kittens, and since there's already too many kittens, it's best to get them fixed.
I meant more tortie males in general seem to be fertile than used to be thought.
Maybe I did not word that well and it sounded like I was saying that more chimera tortie males are fertile than had been thought. But I agree there's no particular reason that the chimeras wouldn't be fertile.
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But it seems like, at least the way I remember it discussed, I think it used to be believed that the Klinefelter's type XXY chromosomal abnormality was the cause in the overwhelming majority of tortie males. And most of those are probably infertile. (but not all as you correctly point out). But now it seems there are more who are torties but not XXY, and not infertile.
Good to point out that there is no reason not to neuter a tortie male.
I would add that a tortie male is not likely to father more tortie males!
Maybe I did not word that well and it sounded like I was saying that more chimera tortie males are fertile than had been thought. But I agree there's no particular reason that the chimeras wouldn't be fertile.
'
But it seems like, at least the way I remember it discussed, I think it used to be believed that the Klinefelter's type XXY chromosomal abnormality was the cause in the overwhelming majority of tortie males. And most of those are probably infertile. (but not all as you correctly point out). But now it seems there are more who are torties but not XXY, and not infertile.
Good to point out that there is no reason not to neuter a tortie male.
I would add that a tortie male is not likely to father more tortie males!
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