Genetic diversity slips

Commercial chicken breeds used to produce meat and eggs around the world have lost at least half of the genetic diversity once present among their ancestors, according to a study conducted by an international team of researchers that includes a UC Davis animal scientist.

The Proceedings of the National Academy of Sciences published the study, which was the first experimental analysis of genetic diversity for an entire agricultural commodity.

“The results of our analysis reaffirm the importance of maintaining a healthy genetic reservoir for chickens, as well as all other food-producing animals, through preservation and conservation,” said Mary Delany, study co-author and chair of the UC Davis Department of Animal Science.

— Pat Bailey

Wheat gains protection

UC Davis plant scientist Jorge Dubcovsky led an international team that identified a gene that should protect commercially important wheat varieties from stripe rust, a disease that causes severe crop losses in the United States and other wheat-growing regions.

“We anticipate that introduction of the Yr36 gene into wheat varieties used for making pasta and bread will have broad impact on improving resistance to the fungus that causes stripe rust,” Professor Dubcovsky said.

The journal Science posted the study findings on Feb. 19 on the journal’s Web site Science Express.

The Yr36 resistance gene was discovered in wild emmer wheat, a low-yielding wheat that grows in Israel.

— Pat Bailey

Clue in sea otters’ diet

UC Davis researchers trying to understand the sea otter’s slow recovery in California have found an important clue: Some sea otters feed almost exclusively on animals that raise the otters’ risk of being infected with potentially deadly parasites.

Abalone is sea otters’ preferred food. But in places where otters compete for food, they must eat a variety of prey, such as small crabs, clams, small snails or worms, and they pass those habits to their offspring. The new research, published in the Proceedings of the National Academy of Sciences, found the lowest rates of parasitic infection in sea otters that ate abalone.

“Higher levels of disease may be an unfortunate consequence of adaptations sea otters have made when preferred food is not available,” said Christine Johnson, one of the study’s lead authors and a veterinary epidemiologist at the UC Davis Wildlife Health Center.

— Sylvia Wright