~ They Said It Couldn't Be Done ~

[Jeanway 0]

 

Since mules are supposed to be sterile, much Broohaha is being made over one that gave birth to a foal in Oulmes, Morocco. Horses have 64 chromosomes and donkeys have 62, so a mule is left with 63, an uneven number. Since these can't divide evenly into pairs, a mule shouldn't be able to reproduce.

 

 

"Those tests confirmed that the mother is a mule with each of her blood groups made up of both horse and donkey alleles, or genetic material - in other words she is a true equine/asinine hybrid," veterinary director Gigi Kay told BBC News Online. "It shows that the foal inherited a mixture of horse and donkey chromosomes via the mother's ovum."

 

John Pycock, if that is indeed his real name, is a specialist in equine reproduction at the Royal College of Veterinary Surgeons. He said a birth like this would be "astounding" and he's very skeptical about it. He also mentioned that mules have given birth to embryos transplanted into the womb artificially.

 

Genetically, the foal is about a quarter horse and three quarters donkey.

[cptwright 1]

call me stupid, but i never knew there was a difference between a donkey and a mule, i just thought two different names for the same animal. learn something new everyday.

[Christiantrekfan 0]

Don't worry cptwright, we don't think you're stupid, and you're right, we learn somthing new everyday. Believe me...I played trivial pursuit with some family saturday, and through the whole thing I only got two questions right! But I learned some things.

Anyway, that was off topic. As for the mule having a baby, that's cool! Not only that, but I didn't know that mules were sterile either!

[WEAREBORG4102 0]

Interesting... The donkey allele is Dominant.... Heterozygous therefore... Ok that checks out according to a Punnett square...

 

Might have been a case of disjunction. Have they tested the sex of the animal? This may account for the formation of offspring in the subspecies.

[Yillara Skye 1]

Interesting... The donkey allele is Dominant.... Heterozygous therefore... Ok that checks out according to a Punnett square...

 

Might have been a case of disjunction. Have they tested the sex of the animal? This may account for the formation of offspring in the subspecies.

282289[/snapback]

 

Yeah, it does check out on a Punnetts square, and technically it is possible. But then it makes you wonder about the genetic trait of being sterile, unless after all this time it truly was a myth(but with one missing chromasome, that would be a true since they would not split and then pair up properly).

 

You also have to wonder about the genetic line of the mule...if it were a true equine/asinine mix then it is more unique for it to have conceived(outside of in vitro), but if the balance leaned more towards it being more horse than donkey or more donkey than horse..then the odds of it being able to reproduce seem (at least to me) a little more likely.

 

I agree that testing the sex of the offspring, may reveal some clues. Also if it had not been done, testing the DNA of the parents could reveal the dominating species of each. This could shed light on the likelyhood of a supposedly sterile species reproducing.

[Wishfire 2]

I believe it. Anomalies do happen, therefore a supposedly sterile animal can give birth.

[WEAREBORG4102 0]

Yes, the disjunction of the sex chromosome druing gamete formation may have influenced the birth and the chromosomes needed for the Cen to begin to form the blastula and the nerulation to occur.

[Jeanway 0]

I believe it. Anomalies do happen, therefore a supposedly sterile animal can give birth.

282398[/snapback]

 

"Supposedly", is the keyword here. Obviously she wasn't sterile. So much for the "Expert Opinions."

[WEAREBORG4102 0]

Well it is well known that subspecies cannot mate and produce offspring. This is going to be interesting to see how such an anamoly could occur. This might lead to a a further understanding of genetics disjunction, infertility, and mammalian reproduction.

[Wishfire 2]

It's probably just a genetic mutation. If the offspring can pass it on, then the mutation will probably survive. If the offspring is sterile, then the mutation was a one in a million chance.

[Jeanway 0]

So in HER case HER mutation allowed her to reproduce. Which made her 'Normal' So when HER offspring carried HER abnormal mutation then IT became normal so it's not a mutation any longer, right? So then the mutation has mutated to normalcy, correct?

[Spockstellaiter 0]

I think it was just a mutation too, like some people being born missing toes, or cats having extra toes, the donkey probably got an extra chromosome somewhere

[prometheus 0]

I'm not going to comment, is case is make an @ss of myself (ho ho ho...)

Also, my throat is sore and i'm feeling a little 'horse' (ho ho)

Maybe this discovery is do' key to genetics! I just need some time to mule it over. Sorry - im just hoofing with ya!

Edited November 25, 2004 by prometheus

[Theunicornhunter 2]

You know this is actually a subject I was curious about and had wondered about mules and sterility - the second link here answers my question. Both of these links (and other sites I've looked at) also indicate that a female mule can produce offspring it is just incredibly rare.

 

Male mules don't sire a foal so the mare has to breed with another animal (horse or donkey I guess)

 

I gather the foal discussed in Jeanway's article was sired by a horse.

 

IMH

 

love long ears

 

Humans can also have uneven chromosome numbers - it is usually manifest as a birth defect

 

However, here's an aticle that suggests that it isn't the odd number of chromosomes that causes the sterility.

http://www.naturalselection.0catch.com/Fil...es%20Mules.html

[WEAREBORG4102 0]

Did they check for Poly X syndrome? That would explain her giving birth... trisomy x's can give birth and mostly fertile...