Larry Cogburn, professor of molecular endocrinology in the College of Agriculture and Natural Resources, will be mapping growth-regulating genes in broiler chickens with another $1.8 grant from the U.S. Department of Agriculture (USDA),

Despite the importance of chicken in our diets, Cogburn says, research on the chicken genome lags behind that of other animal genomes.

"The Human Genome Project has placed powerful new tools on everybody's bench top with one notable exception--those of us who work with avian species. The USDA now is placing an emphasis on functional genomics research in chickens," he says. "We have a lot of catching up to do."

Cogburn says he hopes to identify genes important for the regulation of growth and body composition in broiler chickens. Specifically, he is looking for the genes that regulate growth rate, fat deposition and muscle yield, which are unknown at this time.

For this four-year, multidisciplinary, multi-institutional project, Cogburn has formed a consortium with colleagues from the University of Maryland, the University of Georgia and the Institut National de la Recherche Agronomique (the French equivalent of the USDA).

"Our goal is to identify the critical steps in metabolic and endocrine pathways of broiler chickens so they can be genetically selected to produce elite lines of broiler breeders," Cogburn says.

Cogburn proposes to identify these genes by continuing the work he began several years ago using French lines of chickens. These are the best genetic models available, he says.

Assisting with this research at UD is Associate Professor Lídia Rejtö, who will be developing the bioinformatics programs to analyze and visualize gene expression data.

Cogburn took a sabbatical leave in France in 1996 to begin this work, which is centered on gene expression in two distinct genetic populations of chickens. One population was divergently selected for growth rate--the fast growing versus the slow growing. The other population was divergently selected for fatness versus leanness.

"We mated the fastest growing to the fastest growing, and the slowest growing to the slowest growing, the fattest to the fattest, and the leanest to the leanest. We are looking for the genes responsible for these extremes in production traits," he says.

Cogburn plans to return to France shortly to begin another longitudinal study. Eventually, he will identify the genes important for the regulation of growth and body composition through the use of microarrays, which are considered the discovery platform for functional genomics.

"I'll be comparing the expression of thousands of genes in the slow and fast growing birds and in the fat and lean birds with the hope of defining critical steps in key regulatory pathways," Cogburn says.