Texas A&M Researchers “Paint” the Congo African Grey Parrot’s Chromosomes
Posted March 29, 2016
COLLEGE STATION, Texas – Congo African grey parrots are well
known for their intelligence and beloved by many as pets, but
little is known about their genetic make up. Researchers at the
Texas A&M College of Veterinary Medicine & Biomedical
Sciences (CVM) are changing that by studying the parrot’s
chromosomes.
In a paper published in Cytogenetic and Genomic
Research, scientists looked at the Congo African grey parrot’s
chromosomes and compared them to other parrot species from South
America and Australia. “This is the first study of its kind in true
African parrots,” said Dr. Terje Raudsepp, associate professor and
lead author of the study. “So far, analogous work in parrots has
been done in three South American macaws, Australian budgerigars
and cockatiels, and peach-faced lovebirds from Asia and
Africa.”
The study found that Congo African grey parrots were strikingly
similar to Neotropical macaws found in South America. Unexpectedly,
Congo African grey parrots were genetically more similar to
Neotropical macaws, such as the scarlet macaw and the red-and-green
macaw, than parrots from Australia, such as cockatiels and
budgerigars.
“We found that the rearrangements are essentially, but not
completely, indistinguishable from the scarlet macaw,” said Dr. Ian
Tizard, distinguished professor of immunology at the CVM, director
of the Shubot Exotic Bird Health Center, and an author of the
study. “That was a bit of a surprise because you're talking about
an African parrot and a South American parrot. It implies a much
closer relationship between the South American parrots and the
African parrots than we would have predicted.”
Further, Tizard suggested that this genetic similarity could
have originated before Africa and South America were separated over
70 million years ago. The African and South American parrot species
ended up on opposite sides of the world due to continental drift,
yet much of their genome remained similar.
To get a better look at the African grey parrot’s chromosomes,
the researchers “painted” them, using a technique known as Zoo-FISH
(Fluorescence In-situ Hybridization). This color codes a known
genome—in this case the chicken’s genome—and compares it to a less
understood genome, such as the Congo African grey parrot. By
painting the chromosomes with Zoo-FISH, researchers can identify
identical or similar sets of genes between species that get
rearranged during the process of evolution. For example, genes that
are all together on one chromosome of one species may appear on two
different chromosomes in another species.
“Zoo-FISH, or comparative chromosome painting, allows comparison
of chromosomes of different species at a molecular level and
exchange genome sequence or gene mapping data between the species,”
Raudsepp said. “Zoo-FISH shows chromosomal correspondence between
species but also allows indirect transfer of genetic information
from well-studied species, such as the chicken, to species with no
genome sequence information, such as African grey parrots.”
Although the genes’ locations on the chromosome don’t greatly
affect the animal, the comparative location of these genes can give
researchers clues about evolutionary relationships. Species with
genes in similar chromosomal locations are generally more closely
related than those with dissimilar genetic arrangements. “From the
body's point of view, it doesn't matter whether a gene is on
chromosome one or chromosome seven, as long as it's there,” Tizard
said.
Increased understanding of the Congo African grey parrot also
has conservation implications, Tizard said. Although parrots may
look the same, they might be genetically distinct and, in some
cases, separate species. “We're trying to dissect out these
relationships and they're proving to be a little bit more complex
than expected,” he said.
This is the third collaboration between Raudsepp’s research
group and researchers at the Shubot Center, including sequencing
the genome of the scarlet macaw. More collaborations between the
groups are expected in the future, according to Raudsepp. Tizard
agreed and suggested that similar studies could be done on other
exotic birds.
###
Contact Information: Megan Palsa,
mpalsa@cvm.tamu.edu, 979-862-4216, 979-421-3121 (cell)
↑ Back to Top
« Back to Press Releases
