May 5, 2010

Poultry research in Virginia Tech, Virginia, US, has found a model for exploring the molecular basis of traits like growth and reproduction, which moulded the red jungle fowl into a farm animal about 8,000 years ago.

Paul Siegel, an animal scientist who joined the Virginia Tech faculty in 1957, began breeding lines of White Plymouth Rock chickens based on their juvenile body weight. "Throughout my career, I have been interested in studying the relationships between growth, reproduction and immunology of chickens," said Siegel.

Siegel designed an experiment that would create two flocks of common breed chickens: a high-growth line and a low-growth line. Every year he bred the heaviest and lightest chickens with others of similar weight. Today, Siegel's high-growth chickens are nine times larger than the low-growth ones by the time they reach selection age, even though they both originated from the same flock.

In 2004, scientists completed the genome sequence of the red jungle fowl-the same species as the domestic chicken. Researchers throughout the world began to search for genetic markers that determine specific traits in broilers, layers and red jungle fowl. This research has led to factors that have affected the chicken genome through domestication.

According to Siegel, the decades of poultry breeding complete the recent advances in genome sequencing technology.

The research team identified a gene found in all of Virginia Tech's high-growth chickens but few of the low-growth ones that appears to regulate appetite-a finding that could have ramifications for both animal and human health studies involving weight. Previous research has shown that appetite, in addition to metabolism, plays a significant role in weight gain or loss in poultry.

Virginia Tech has the populations to support the use of the technology and they also have the complete pedigree for 53 generations.