An agency effort to sequence genomes: unraveling the genome of the honey bee, pig, cow, and chicken

Agricultural Research, Jan, 2005 by David Elstein, Don Comis, Jan Suszkiw, Alfredo Flores

Humans have a vested interest in Apis mellifera; the honey bee's pollination of 90-plus flowering crops results in yield and quality improvements worth more than $14 billion annually. And don't forget the delectable byproduct of such pollination: honey.

Many dangers, from blood-sucking mites to disease organisms, constantly threaten to undermine the honey bee's efforts, keeping scientists on a fast-track search for new ways to safeguard the insect--and agriculture, no less. Now, a rough draft of A. mellifera's genome is at hand, and bee researchers are gobbling up the wealth of information.

"As an organism whose social order rivals our own in many ways, the honey bee will serve as a natural system for further agricultural studies, including social behavior, cognition, and immune system function," Joseph Jen, Under Secretary for USDA's Research, Education, and Economics, noted shortly after the genome draft's January 2004 completion.

The honey bee's entire blueprint for life is only about one-tenth the length of the human genome. Still, writing that first draft was no easy task; the feat took a dedicated team of scientists--led by Baylor College of Medicine in Houston--about a year to complete using the latest in genome-sequencing technology and several million dollars in funding.

Kevin Hackett, ARS's national program leader for bees and pollination in Beltsville, Maryland, lists some of the exciting new research avenues that the honey bee genome has opened up: identifying genetic markers to expedite bee-breeding efforts, for example, to improve crop pollination, winter survival, and defensiveness against Africanized bees; host-pathogen modeling studies to better control organisms that cause honey bee diseases; and genome-driven studies to fine-tune honey bee nutrition and pollination.

"If you can locate the 'smelling' genes of bees," says Hackett, "you can use the information to improve their diet through supplementation as well as their ability to forage--with greater pollination resulting."

Jay Evans and Katherine Aronstein, ARS entomologists who participated in the honey bee genome project, are using information from the advance to identify immune system genes that keep bees healthy. Of particular emphasis is characterizing genes involved in potential resistance to the bacterium Paenibacillus larvae, which causes foulbrood disease in honey bee larvae. Along with insect pests, parasites, and other pathogens, foulbrood outbreaks in U.S. hives cause $5 million annually in crop-pollination losses.

At their respective labs in Beltsville and in Weslaco, Texas, Evans and Aronstein are studying a handful of genes and gene products, or proteins, that may stymie honey bee diseases. One tantalizing lead is abaecin, a peptide that honey bees produce to varying degrees when attacked by pathogens.

"We know these bees are responding to foulbrood by producing abaecin," Evans says. "But we're not sure whether a bee that produces more of this peptide is indeed foulbrood resistant."