January 01, 2003


 Mapping the bovine genome to help humans, cattle

Posted Dec. 15, 2002

Guided by the bovine genome, scientists may soon be able to improve production traits in cattle and possibly help provide solutions to certain human health problems. Scientists with the Department of Agriculture's Agricultural Research Service and their colleagues around the world have been mapping the bovine genome.

The project began in spring 2000 when Steven M. Kappes, PhD, director of the ARS Roman L. Hruska U.S. Meat Animal Research Center in Clay Center, Neb., began contacting laboratories around the world to develop a Bacterial Artificial Chromosome map. Bacteria—specifically, bacterial chromosomes, are used as hosts for pieces of bovine chromosomes. Scientists use the bacterial hosts to generate many identical copies of a piece, or clone, of cattle DNA. The BAC map will help them to identify genes that affect production traits in farm animals and to sequence the bovine genome.

The first step is fingerprinting each of 280,000 BAC clones. The second step, which can occur simultaneously, is sequencing both ends of all the BAC clones. Scientists will combine the end sequencing and fingerprinting information to determine the overlapping BAC clones.

So far, 249,000 of the cattle BAC clones have been fingerprinted, and the end sequencing effort is under way. The bovine BAC map is scheduled for completion in February 2003.

The project should enable scientists to be more accurate when they select genetically superior animals for specific purposes such as lean beef, milk production, or reduced feed requirements. With cattle and humans having many of the same genes, this research may also help the medical community. Researchers will be able to compare the genetic maps of each species to seek cures for diseases.