

USDA Scientists Rapidly Expand Database of Gene SegmentsBy Ben Hardin July 10, 2000CLAY CENTER, Neb., July 10Progress by a team of
Agricultural Research Service scientists
shows that biotechnologys best shot at improving livestock may be to help
conventional breeders identify genetically superior animals. This team of 15 scientists is generating a vast amount of
new genetic information thats being shared with researchers around the
world, said Floyd P. Horn, administrator of ARS, the chief research
agency of the U.S. Department of
Agriculture. The team is based at the Roman L. Hruska U.S. Meat Animal Research
Center (MARC) operated by ARS at Clay Center. The teams findings are
accessible through the databases of the National Center for Biotechnology
Information (NCBI) Genebank in Washington, D.C., and databases at the Clay
Center facility. In the past year the team has deciphered 50,000 gene sequences in
the cattle genome, and more than 30,000 sequences in swine. Within the next
three months, the scientists hope to add 30,000 additional sequences from
cattle and 10,000 from swine. The numbers to date represent about 95 percent of the publicly
available information on DNA segments called expressed sequence tags (ESTs) for
cattle and almost 90 percent for swine, according to Dan B. Laster, who retired
as director of the Clay Center facility on June 30. Laster began assembling the
Clay Center team in the early 1990s. ESTs represent significant parts of genes that determine the
proteins produced by certain tissues. Most of an animals DNA never
seems to do anything, said biochemist Timothy P. Smith, who leads the ARS
team. So the scientists focus on 2 to 5 percent of the DNA thats turned
into RNAs--ribonucleic acids--which are an intermediate step in making
proteins. A similar but smaller effort is also being conducted by an ARS
group in Beltsville, Md. That group is sequencing genes that function in the
mammary gland of dairy cattle. The Maryland group is working to identify all of
the genes responsible for milk productivity traits and the genes that cause
superior animals to produce larger quantities of milk proteins in their mammary
glands. By using computers to compare gene sequences from different cows, the
researchers will sort out the genes that control milk composition. The Clay
Center and Beltsville groups work together to deposit the information into the
NCBI and Clay Center databases. According to Steven M. Kappes, a recent member of the MARC genomic
team and now ARS National Program Leader for Animal Production and Germplasm,
each of many genes may have a small impact on an inherited trait, but when
added together they may have great economic importance for a herd and for the
livestock industry. The accelerated pace of gene mapping stems partly from successes
by international scientists in the much larger Human Genome Project. Humans and
livestock basically have the same genes, but with small differences in
sequences and arrangement on chromosomes. Comparisons and contrasts between
gene sequences of various species are helping biomedical researchers learn how
proteins work and how the human body works, said Kappes. Scientific contact: Timothy P. Smith, ARS
Roman L. Hruska U.S. Meat Animal Research
Center, Clay Center, Neb., phone (402) 762-4366, fax (402) 762-4390,
[email protected]. U.S. Department of Agriculture |