[Homestead] Mule's foal fools genetics

Jerry W. Shepperd shepperd at austincc.edu
Tue Jul 31 18:27:40 EDT 2007


At 10:48 AM 7/30/2007, you wrote:
>I heard a news report that a mule recently gave birth,
>haven't seen anything about it in printed media.
>Anyone else aware of this??
>Van Dell

The Denver Post has this article:
http://origin.denverpost.com/breakingnews/ci_6464853
Mule's foal fools genetics

It's an event so rare that the Romans had a saying, "when a mule 
foals" - the equivalent of "when hell freezes over."
<mailto:nlofholm at denverpost.com?subject=The Denver Post: Mule's foal 
fools genetics>By Nancy Lofholm, Denver Post Staff Writer
Article Last Updated: 07/26/2007 06:33:16 AM MDT

<http://origin.denverpost.com/breakingnews//portlet/article/html/imageDisplay.jsp?contentItemRelationshipId=1598085>
[]

Colbran rancher Larry Amos watches as the mule foal nuzzles its 
mother, Kate, a 7-year-old "molly" that gave birth three months ago 
to the still-unnamed "miracle" offspring. Genetic tests confirmed 
that the foal is Kate's. (Ed Kosmicki | Special to The Post)

Colbran - When it reportedly happened in Morocco five years ago, 
locals feared it signaled the end of the world. In Albania in 1994, 
it was thought to have unleashed the spawn of the devil on a small village.

But on a Grand Mesa ranch, the once-in-a-million, genetically 
"impossible" occurrence of a mule giving birth has only drawn keen 
interest from the scientific world. That, and a stream of the locally 
curious driving up from the small town of Colbran to check out and 
snap pictures of a frisky, huge-eared, gangly-legged foal.

"No one has run away in fear yet," laughed Laura Amos, the owner of 
the foal, along with her husband, Larry.

The foal is being called a miracle because mules aren't supposed to 
give birth. Mules are a hybrid of two species - a female horse and a 
male donkey - so they end up with an odd number of chromosomes. A 
horse has 64 chromosomes and a donkey has 62. A mule inherits 63. An 
even number of chromosomes is needed to divide into pairs and reproduce.

But those numbers added up to implausibility in late April when the 
Amoses awoke to a braying and whinnying ruckus in the corral behind 
their house.

Running to the rescue

They spotted a foal peeking out from between the front legs of one of 
their favorite black mules, Kate. They tore outside to save the baby 
from the male mules - the johns - that were trying to stomp the 
little critter and the other female mules - the mollies - that were 
trying to steal it.

And then the Amoses began to ponder how the foal had fooled mule 
sterility, a phenomenon first noted by the Greek philosopher Aristotle.

The Amoses, who have about 100 horses and mules at their Winterhawk 
Outfitters business, knew that what they were seeing is considered 
scientifically impossible - as much so today as in ancient Greece. 
They began doing research and found that in the past two centuries 
about 50 cases of mules giving birth have been recorded. Only two of 
those were proved with genetic testing.

It's an event so rare that the Romans had a saying, "cum mula 
peperit," meaning "when a mule foals" - the equivalent of "when hell 
freezes over."

Genetic testing at the University of Kentucky and the University of 
California at Davis confirmed that Kate is indeed a mule and that the 
still unnamed foal really is her offspring. That ruled out factors 
that have explained away some of the past births mistakenly 
attributed to mules. Those mules had stolen foals or they were not 
really mules themselves. They were donkeys or mulish-looking horses.

Now, the Amoses are waiting for chromosome testing from the 
University of California to determine exactly what is the 
fast-growing foal cavorting clumsily around their corral. He could be 
a smidgen of horse and a lot of donkey or mostly horse with just a 
bit of donkey genes.

"He's got a donkey look now, but they all do at that age," Larry Amos said.

Surprise findings

Dr. Oliver Ryder, associate director of the Conservation and Research 
of Endangered Species division at the San Diego Zoo, said the answer 
to how Kate could give birth could be surprising. There were very 
unexpected - and still unexplained - findings when a molly mule gave 
birth to two foals in Nebraska in the mid-1980s. The event prompted 
notice from the local pulpit and a flurry of scientific 
investigation, including the first genetic testing of a mule's offspring.

Ryder said that tests in the Nebraska case showed there was no 
evidence the mother passed along any genetic markers from her father 
- a donkey that was also the father of the foals. The phenomenon is 
called "hemiclonal transmission," which in simple terms means that 
the mare's genes canceled out the male's genes as if they didn't even exist.

That phenomenon has been observed in amphibians but not in mammals.

"No recombinations took place. There was no reassortment. We looked 
at markers on every chromosome," Ryder said. "This was an extremely 
unexpected finding."

Another famous but scientifically undocumented case occurred at Texas 
A&M in the 1920s. A mule gave birth to a mule when the sire was a 
donkey and then to a horse when the sire was a stallion.

Ryder said he is "fascinated by this phenomenon" and is looking 
forward to learning more from the Amoses' foal.

So is the mule publication "Mules and More," which is running a 
contest to name the foal and has promised readers regular updates.

The Amoses are still scratching their heads. They didn't know Kate 
was pregnant when they bought her and nine other mules from a breeder 
in Pleasant Plains, Ark., late last summer. She worked as a pack 
animal through the winter, and no one noticed when the animals were 
brought in this spring that she was pregnant. They were all fattened 
from a winter of good feed.

The Amoses are talking about breeding Kate again. They want to see if 
the "miracle" will occur twice. They say they have no fear that it 
will bring on the end of the world.


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