University of Texas at Arlington team exploring pigeons as a model for
vertebrate evolution has uncovered that mutations and interactions among just
three genes create a wide range of color variations. One of those genes, they
also found, may be an example of a “slippery gene” more prone to evolutionary
A research team led by John W. "Trey" Fondon, a UT Arlington assistant professor of biology, recently published a study on gene mutation in pigeons.
John W. “Trey” Fondon, an
assistant professor of biology, is co-author of a study that begins to unravel
the molecular basis for the color palette of domestic pigeons breeds known as
“fancy pigeons.” Due mostly to organized breeding in Europe and Asia, there are
hundreds of types of pigeons that have evolved to include numerous color
variations on the blue/black model, including shades of gray, red, and brown.
in the study have previously been linked to skin and hair color variation
among people, as well as the development of melanoma.
pigeon really has been neglected as a model system, and we are changing that,”
Fondon said, adding that such studies can help in an overall understanding of
vertebrate systems. “The things that shape diversity also shape disease.”
The results are being published
online Feb. 6 in the journal Current
Biology. Eric T. Domyan, a post-doctoral fellow in the lab of University of
Utah professor Michael D. Shapiro, is lead author.
Other co-authors include
Shapiro; Shreyas Krishnan and Clifford Rodgers, of UT Arlington; Zev
Kronenberg, Michael W. Guernsey, Anna Vickery and Mark Yandell, of University
of Utah; Raymond E. Boissy, of the University of Cincinnati College of
Medicine; and Pamela Cassidy and Sancy A. Leachman, of the Oregon Health &
Shapiro’s team at University of
Utah published research last year in the journal Science that revealed results from the first large-scale sequencing
of the pigeon genome. That collection of more than 100 billion DNA bases from
40 pigeons, provided the basis for the new work.
Geneticists like Fondon have
turned to dog breeds in the past to understand the molecular basis of phenotype
changes because dog breeds are so varied. Fondon said scientists hoping to
understand more about how characteristics vary can find even greater
statistical power and diversity in studying domestic pigeons.
Fondon’s laboratory worked in
parallel with researchers at Utah to find that coding and regulatory variations
in the interactions among the genes Tyrp1, Sox10 and Slc45a2 control multiple
color phenotypes, or appearances, in pigeons. For example, researchers found
that the ash-red mutation in Tyrp1, a gene that plays a large role in color
determination, arose just once and was spread throughout the species by
They also found that some color
changes evolved through changes in the same gene that happened at different
times – hinting at the existence of a “slippery gene.”
Fondon's team found two
independent deletions of regulatory sequences near the Sox10 gene produce
“recessive red” pigmentation. These mutations happened at different points in
evolution, and researchers believe it is no coincidence they hit the same spot,
as this same region is also deleted in color mutants of chickens and mice,
Fondon said. There are indications of yet more independent mutations of this
More research is needed, but
Fondon expects significant progress in understanding is on the horizon.
“These traits are falling like dominoes in
terms of our understanding their genetic origins. It took hundreds of years to
set them up and now they are just falling,” Fondon said.
The name of the new paper is
“Epistatic and combinatorial effects of pigmentary gene mutations in the
Fondon is contributing important, essential discoveries to our understanding of
how genes change over time. His work is strengthening our already vibrant
Genome Biology Group and the College of Science overall," said Pamela
Jansma, dean of the UT Arlington College of Science.
Work on the study was funded by
several agencies, including the National Institutes of Health, the National
Science Foundation, the Huntsman Cancer Foundation, the Tom C. Mathews, Jr.,
Familial Melanoma Research Clinic Endowment and the Burroughs Wellcome Fund
Career Award in the Biomedical Sciences.
About UT Arlington
The University of Texas at Arlington is a comprehensive research
institution and the second largest institution in The University of
Texas System. Total research expenditures reached almost $78 million last
year. UT Arlington ranks fifth in the nation for undergraduate diversity and
was ranked as the seventh fastest-growing public research university by
The Chronicle of Higher Education in 2013. Visit www.uta.edu to learn more.