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Since Watson and Crick first discerned the structure of DNA 50 years
ago, scientists have been studying it, hoping to unravel the mysteries
of animal and plant growth and reproduction. Agricultural scientists
have constantly sought to put the burgeoning knowledge to practical
purposes, breeding animals with natural resistance to disease or ones
that produce more efficiently.
In the beginning, decoding the series of genes that make up DNA strands,
unique to each living organism, was very slow and tedious. In the early
1980s, tools such as polymerase chain reaction and short tandem repeat
DNA markers started us in the right direction.
The late 1980s and early 1990s saw DNA technology evolve rapidly, thanks
to large amounts of money being dedicated to human genome study. A genome
is all the genetic information or hereditary material possessed by an
organism. Scientists hope that by learning about the genes that make
a human being—and the roles they play in health and growth—it
may be possible one day to cure hereditary problems, such as Tay-Sachs
disease, various forms of cancer, and Parkinson's.
Concurrently, scientists in the animal-research community began working
with counterparts involved in human genomic studies. The quality and
speed of DNA analyses were aided by development of improved, automated
sequencing technology. Greater computer capabilities and specialized
software made it feasible for researchers to manage the huge amount
of data generated by DNA analyzers, doing in days or weeks what previously
took months in a laboratory.
Today, with agencies and universities from several countries helping
to conduct it, animal genomic research has become a worldwide effort.
One of my responsibilities is to represent ARS
and USDA as a member and executive secretary of the Interagency Working
Group on Domestic Animal Genomics. The group, formed in 2002, coordinates
the genomic research of eight U.S. federal agencies through the National
Science and Technology Council, a cabinet-level council that creates
science and technology policy for the U.S. government.
For fiscal year 2004, Congress appropriated more than $33 million for
ARS's animal genomics research. It represents a great investment in
the agency that has already quickened the pace of genomics research.
Soon, research that took 10 years to complete in the 1980s may be completed
in just a few years. And application of this new knowledge may range
from producing consistently tender steaks to preventing human diseases.
Scientists are now—or shortly will be—sequencing the genomes
of the cow, pig, honey bee, and chicken. This work will help to pinpoint
all the genes and, eventually, the various functions they govern. Sequence
maps will make it possible to more easily unravel interactions between
genes. Quantitative geneticists have theorized for decades that it's
these interactions that create the phenotypic effects that are economically
important.
Many animals are genetically similar to each other. Sheep and goats
are ruminants and are genomically similar to cows. Likewise, turkeys
are similar to chickens. So researchers already have the advantage of
knowing a lot about these animals without having to spend time and money
physically mapping the location of each and every gene.
The Interagency Working Group is beginning to explore the possibility
of sequencing the catfish, rainbow trout, and Pacific oyster. Nonagricultural
animals, such as the mouse and dog, have already been mapped by other
groups. Agency researchers are able to access and use this information
as well.
The article beginning on page
4 illustrates the genomic work that ARS—with collaborators
from around the world—has already accomplished with these animal
species. The objectives of genetics and genomics research extend far
beyond the traditional goal of producing adequate quantities of safer,
better, and cheaper food. Completed maps will allow scientists to compare
the genetic makeup of these agriculturally important animals to learn
more about each of them—and to learn more about humans.
They will also learn ways to improve the health and well-being of farm
animals. In an age of bioterrorism threats, it is also necessary to
understand the genes that will react if livestock are ever endangered
by biological agents.
The National Institutes of Health is a major collaborator with ARS,
particularly because of the potential human health benefits that may
arise from animal genomic research. For example, completion of the chicken
genome will provide a valuable model for human embryology and development
as well as for study of reproductive diseases. It should also help to
expand knowledge of cancer and other diseases. Researchers study the
honey bee because it's a good model for aging. Scientists want to study
the honey bee's nervous system as well.
ARS continues to be highly interested in research to produce more efficient
animals. Tools developed from genomics research will allow better identification
of the proper animal for any particular production system and environment.
That will lead to more efficient raising of higher quality meat animals
at lower prices to the American and worldwide consumer.
Ronnie D. Green
ARS National Program Leader
Food Animal Production
Beltsville, Maryland
"Forum" was published in the January
2005 issue of Agricultural Research magazine.
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