The potential to selectively and accurately breed cattle for specific
traits such as improved meat yield or tenderness has been greatly
enhanced with the release of the first draft of the bovine genome
sequence. Scientists say that this work, which is now available
to researchers in public databases, will underpin cattle research
for the next several decades. A team led by Richard Gibbs, Ph.D.,
at Baylor College of Medicine’s Human Genome Sequencing Center
in Houston carried out the sequencing and assembly of the bovine genome.
“You won’t have to be a genomics expert to profit from
this research,” said Paul Genho of King Ranch in Kingsville,
Texas. “The potential is huge. We now have a roadmap that researchers
can reference for almost anything they want to know about the beef
genome. This tells scientists exactly where they can locate
many of the traits they want to study.”
Cattlemen, through their $1-per-head beef checkoff program, will have
provided about $600,000 of the $53 million funding for the project. The
Texas and South Dakota Beef Councils also contributed funding to the
research consortium, which included the federal government, four countries
and private industry.
The genome sequence project was conducted on behalf of the Cattlemen’s
Beef Board and state beef councils by the NCBA.
A simplified example of genome sequencing would be to compare it to
trying to find an old high school buddy (find a gene for tenderness). We
know that he lives somewhere in Colorado (in the bovine genome). We
use DNA markers and gene mapping to find out that he is located in
the Denver metro Area -- somewhere between the suburbs of Littleton
and Lakewood (marker satellites are Littleton and Lakewood). If
we can sequence the Denver metro area, we can identify every person
in the Denver metro area and locate their address -- including our
lost friend whom we now can visit.
By sequencing the genome, scientists will be able to isolate and further
investigate the traits specific genes provide cattle breeders. Clare
Gill, Ph.D. and a researcher at Texas A&M University, says scientists
already are using this research to study things like quality traits
that will help cattlemen make desired changes in their herds with
more predictability.
Cattlemen already have identified a genetic marker for tenderness
and some breed organizations participated in research to determine
the heritability of this trait. The study showed that tenderness
is a heritable trait, but there were differences between and within
breeds on the degree of heritability.
The bovine genome contains approximately 3 billion DNA base pairs
and an estimated 25,000 genes. Sequencing of the bovine genome
began in December 2003 on a Hereford animal. Scientists plan to sequence
the genomes of the Holstein, Angus, Jersey, Limousin, Norwegian Red
and Brahman breeds. ©
