April 23, 2009

Scientists sequence the bovine genome

A U.S.-led international consortium of scientists says it has sequenced the bovine genome, showing the genetic features that separate cattle from humans.

The six-year effort has produced the first full genome sequence of any ruminant species, officials said, consisting of at least 22,000-protein coding genes and is more similar to that of humans than to the genomes of mice or rats.

University of Illinois Professor Harris Lewin said the cattle genome appears to have been significantly reorganized since its lineage diverged from those of other mammals.

Among the mammals, cattle have one of the more highly rearranged genomes, Lewin said. They seem to have more translocations and inversions (of chromosome fragments) than other mammals, such as cats and even pigs, which are closely related to cattle.

The sequence of the cow's 29 pairs of chromosomes and its X chromosome -- the Y chromosome was not studied -- also provides new insights into bovine evolution and the unique traits that make cattle useful to humans, Lewin said.

The research -- coordinated by Richard Gibbs and George Weinstock of the Baylor College of Medicine, Chris Elsik of Georgetown University and Ross Tellam of the Commonwealth Scientific and Industrial Research Organization of Australia -- is featured in the journal Science.