November 21, 2011
Elizabeth Kowalski ’12, left, and Taryn Cranford ’12, right, with Associate Professor Rebecca Bellone, middle, demonstrate methods used in Bellone’s research.
Kowalski , left, and Cranford, right, with Bellone, middle, demonstrate how to use a DNA genetic analyzer, a tool used in Bellone’s research.
In 1997 Rebecca Bellone was a new graduate student at the
University of Kentucky, at the start of what would become a lifelong study of
the genes responsible for Appaloosa spotting in horses.
She remembers giving her first presentation, which started
with the notion that the genetic mutation responsible for spotting in horses’
coats is thought to have existed at the end of the last ice age, as exemplified
by cave paintings in Perch-Merle, France, but in 1997 this couldn’t be tested.
This month, a team of researchers she collaborates with published findings in the Proceedings of the National Academy of Sciences that show the gene
mutation existed in the ice age. This was a full-circle moment for Bellone.
“To collaborate on this project has been fun and exciting as
this is a question that has intrigued me for as long as I have been studying
this spotting pattern,” said Bellone, an associate professor of biology.
There is debate about what cave paintings like those in
Pech-Merle represent: true life depictions or artistic creativity.
Anthropologists are interested in the research because proving these horses existed
thousands of years ago might mean the other animals depicted – like mammoths –
would have existed and gives clues as to what these animals may have looked
like in that location at that time as well.
This is important because it begs the question – how does a
mutation endure so long when mutations that typically make an animal weaker die
out? This was the thought with Appaloosa spotting, which has been associated
“It suggests there must be an advantage,” said Bellone,
guessing the spotting patterns helped to camouflage the horses in snowy environments,
or perhaps something less obvious like it caused a behavioral or immunological advantage.
“The most exciting thing about science is that you don’t know how one finding
can lead you down another different and exciting road.”
Bellone was sought out to participate on the international
research team exploring ancient DNA in horses lead by Arne Ludwig from the
Leibniz Institute for Zoo and Wildlife Research.Monika Reissmann, one of the team’s members,
remembered meeting and seeing a presentation of Bellone’s on the leopard
complex spotting gene associated with Appaloosa spotting at a July 2008
conference of the International Society of Animal Genetics in the Netherlands.
In 2009, Bellone was asked to join the 11-member study because
of her specialty with the leopard complex spotting. It was in her University of
Tampa lab where she made the discovery that an SNP (single nucleotide
polymorphism or one change in the sequence of DNA) was associated with the
leopard complex spotting.This
polymorphism was used to determine if the genetic mutation for this spotting
pattern existed in the wild ancient horse DNA.
Working with ancient DNA poses challenges because
contaminating samples means history lost. Also, the samples are degraded over
time so scientist are only able to get small fragments of DNA to read, which
requires different testing methods.
“It makes it trickier to work with, but my collaborators are
experts in working with a DNA” said Bellone, who had never worked with ancient
Several UT students have been involved in this study, extracting
DNA from modern horses and testing reactions that lead to the discovery of the
To learn important molecular biology techniques in her molecular
biology laboratory course, Bellone’s students genotype horses for this mutation
and determine if night-blindness is present as well.
“Science is an
adventure,” said Bellone. “For me, this particular study has been really fascinating.”
Jamie Pilarczyk, Web Writer
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