Researchers have unraveled the genetic sequence of the Red Jungle Fowl, an ancestor of domestic chickens. (Photo courtesy National Human Genome Research Institute)

By Lisa D. Tossey
Maryland Newsline
Tuesday, March 9, 2004

A team of international scientists announced last week that it has cracked the chicken’s genetic code, a development that could aid in the fight against avian flu.

The researchers have assembled the genome of the Red Jungle Fowl (Gallus gallus), an ancestor of domestic chickens, and have placed the genetic sequence in a public database for use by other scientists.

It is the first bird genome to be completed, and includes about 1 billion base pairs of DNA, the molecules that carry genetic information necessary for the organization and functioning of most living cells. By comparison, the human genome spans about 3 billion pairs.

The research team, led by Richard Wilson of the Washington University School of Medicine in St. Louis, is now “annotating, filling in the blanks and analyzing” the initial assembly of the sequence, said Geoff Spencer, a spokesman for the National Human Genome Research Institute, which funded the research.

“Even in a rough draft form, it can help,” Spencer said. “Research will be accelerated by having this tool.”

Recent outbreaks of avian flu throughout the world have increased interest in how genetic variation plays a role in the resistance levels of different birds. Researchers will now be able to use the genome to identify genes that might help chickens ward off various strains of the flu, they say.

Mo Saif, a poultry disease expert with the Ohio Agricultural Research and Development Center, said having the sequence will aid research in finding chickens that have such resistance. But he warns: “The benefits will not be immediate. The more accurate and inclusive the sequence becomes, the better.”

Poultry farmers in Maryland were on edge following a weekend avian flu outbreak in Pocomoke City, Md. The strain of flu found on the Worcester County farm, known as H7, does not pose a threat to people but can be deadly to the birds. It is the same strain that was found on two Delaware poultry farms last month, said Julie Oberg, a spokeswoman for the Maryland Department of Agriculture.

Oberg said 118,000 birds were humanely killed on the affected farm Sunday. Another 210,000 birds that tested negative for the flu on a related farm will be destroyed as a preventative measure.

The poultry industry is Maryland’s largest agricultural sector, accounting for 31 percent of the state’s $1.4 billion agricultural industry, Oberg said. Nationwide, Maryland ranks seventh in broiler production, she said.

In addition to their role in farming, chickens are also widely used in biomedical research and as a model for studying embryology and development. The Washington University team has lined up the Gallus gallus genome with the human genetic sequence, allowing scientists to compare them. By examining the two genomes, researchers can to look for similar gene sequences that can help them develop new ways to combat human disease.

Copyright © 2004 University of Maryland Philip Merrill College of Journalism