RESEARCH Science Agriculture

GENETICS
Human, cattle genome map shows many genes configured similarly

Jim Barlow, Life Sciences Editor
(217) 333-5802; b-james3@uiuc.edu

10/1/2000

CHAMPAIGN, Ill. -- Animal scientists studying the genes of cattle say their first-ever comparative map of cattle and human genomes show that many genes -- even whole chromosomes -- are configured in the same way in the two species.

"The comparative map has enormous predictive power," said lead researcher Harris Lewin, director of the W.M. Keck Center for Comparative and Functional Genomics at the University of Illinois. "For the first time, we can move from a point on the human genome to the equivalent point on the cattle genome. That will allow us to use the map of one species to identify genes controlling important traits in the other, such as those influencing lactation, reproduction and resistance to infectious diseases."

The comparative map and a second map, providing an up-to-date look at the cattle genome, were published in the September issue of the journal Genome Research. A pullout poster of the comparative map was included in the journal, courtesy of AniGenics Inc., an animal genomics company, and Research Genetics, a major supplier of tools and reagents for genome research and subsidiary of Invitrogen Corp.

Lewin is a professor of animal sciences, holder of the Gutgsell Endowed Chair and director of the UI Biotechnology Center. His team included co-authors Mark R. Band, a postdoctoral research associate; Joshua H. Larson, a graduate student in the UI department of animal sciences; and James E. Womack, the W.P. Luse Endowed Professor at Texas A&M University.

The research -- funded by the USDA National Research Initiative -- combined the sequencing of small segments of genes and sophisticated bioinformatics tools developed at the UI with a radiation hybrid cell panel, a unique resource for gene mapping developed in Womack's laboratory.

A total of 1,087 genetic markers, including 768 known genes, were mapped. About 92 percent of all cattle chromosomal DNA was included, representing a four-fold increase in the number of previously mapped cattle genes, Lewin said. Among the known genes, 638 (83 percent) could be identified as identical to human genes that also have positional information on human chromosomes.

The comparative map revealed that up to 149 conserved chromosome segments in humans and cattle, including four whole chromosomes, appear to have the same genes in both species, despite the two species being separated by more than 60 million years of evolution.

Eventually, Lewin said, the cattle genome will be completely sequenced. "In the end" he said, "we will understand the molecular genetic basis for the major phenotypic differences among the mammals. This will have enormous scientific and practical significance.

"Breeding cattle for resistance to infectious diseases, for instance, would reduce our dependence on antibiotics in feed, a major concern for human health and food safety," he said.