Gene chips for cows

Scientists at several U.S. and Canadian research institutes arecollaborating with Illumina, based in San Diego, CA,to develop a bovine gene chip, similar to those used to study the genetics ofhuman disease. The DNA chips, will dramatically speed the search for the genetic variants that underliedesired traits, such as the level of marbling in a cut of meat or theefficiency of a dairy cow's milk production.

"Thisopens a whole new scale of gene identification in cattle," says JerryTaylor, professor of animal genomics at the University of Missouri-Columbia and one of the researchers on the project. "We'll be able to tacklegenetics of all of these traits--reproductive capability, milk production, milkcomposition, and quality of meat--in ways we never before envisioned."

Thesequence of the cow genome was released last year, but scientists have madelittle progress in identifying genes associated with desirable bovine traits,for the same reasons that have slowed human studies of complex geneticdiseases: vast amounts of genetic data are needed to narrow down the gene variantslinked to a particular trait.

Nowscientists are planning to pool data from revised drafts of the bovine genomeand other studies to create this genetic tool--a tiny glass chip coated withthousands of short sequences of DNA that can detect sites in the genome thatfrequently differ among individuals. Researchers at the U.S. Department ofAgriculture, University of Missouri-Columbia,and University of Alberta are now choosing the specific sequences that will be included on the chip.

The chips will allow scientists to quickly and cheaply gather genetic data on hugenumbers of cattle. Scientists can take a DNA sample from an animal and use thechip to simultaneously detect thousands of genetic variations, giving adetailed profile of that animal's genome. Thousands of individual profiles arethen analyzed in conjunction with data on each animal's phenotype (itsobservable, physical characteristics) to determine the variations associatedwith a particular characteristic, such as growth rate.

Source: technologyreview.comAdded: 12 October 2006