30 October 2006
U.S. Agencies Fund Project To Sequence Honeybee Genome
Consortium of 170 investigators from 13 countries publish draft genome
Washington -- A research consortium supported by the National Human Genome Research Institute (NHGRI), an entity within the U.S. National Institutes of Health (NIH), published a draft genome sequence of the western honeybee, finding that its genome is more similar to humans than any other insect sequenced so far.
NHGRI provided $6.9 million for the project and the U.S. Agriculture Department contributed $750,000. The National Institute of Allergy and Infectious Diseases and the National Library of Medicine, both part of NIH, provided more support.
The honeybee’s social behavior makes it an important model for understanding how genes regulate behavior through the development of the brain and central nervous system, according to NIH October 26.
“Comparing the genome of the honey bee with other species separated over evolutionary time from humans,” said NHGRI Director Dr. Francis Collins, “has provided us with powerful insights into the complex biological processes that have evolved over hundreds of millions of years.”
Understanding the bee genome might lead to important insights into common mental and brain disorders, such as depression, schizophrenia or Alzheimer’s disease. The bee genome also might provide an important window into immunity and aging.
HONEYBEE DNA
In a paper published in the October 26 issue of the science journal Nature, the Honey Bee Genome Consortium, led by Richard Gibbs, director of the Human Genome Sequencing Center at Baylor College of Medicine in Texas, describes the 260 million DNA-base-pair genome of the honey bee (Apis mellifera).
A base pair consists of two main chemicals that together form a rung of the DNA twisted ladder, the double helix. A DNA nucleotide is made of a molecule of sugar, a molecule of phosphoric acid and a molecule called a base.
The bases are the letters that spell out the genetic code. In DNA, the code letters are A, T, G and C, which stand for the chemicals adenine, thymine, guanine and cytosine. In base pairing, adenine always pairs with thymine, and guanine always pairs with cytosine.
Although only 9 percent the size of the 3 billion base pairs in the human genome, the honeybee contains nearly half as many genes as the human genome, more than 10,000 in the bee compared to around 20,000 genes in the human.
The honeybee is the third insect to have its genome sequenced and analyzed.
The malaria-carrying mosquito (Anopheles gambiae) was completed in 2002 and the fruit fly (Drosophila melanogaster), an extensively used model organism in genetics research, was completed in 2000.
The honeybee genome is 50 percent larger than that of the fruit fly but contains roughly the same number of genes. Sequencing of the honeybee genome began in early 2003.
“The genome of the honeybee has been added to a growing list of organisms whose sequence can be compared side by side to better understand the structure and functions of our own genes,” Collins said. "And that will help speed our understanding of how genes contribute to health and what goes wrong in illness.”
COMPARING GENOMES
In the analysis, the researchers report that the honeybee has evolved more slowly than the fruit fly or the mosquito and contains 10,157 known genes.
When compared to other insects, the honeybee genome contains fewer genes involved in innate immunity, detoxification enzymes and taste receptors, and more genes for olfactory (sense of smell) receptors and novel genes for nectar and pollen use.
The honeybee genome is more similar to those of vertebrates than it is to the genomes of insects for genes involved in circadian rhythm – an in-born 24-hour cycle that controls biological processes like sleep and digestion and hormone activity -- and biological processes involved in turning genes on or off.
The honeybee is used widely in agricultural and biomedical research and is valued by farmers for its ability to produce honey and pollinate crops.
The honeybee is also a model organism for studying human health issues, including immunity, allergic reaction, antibiotic resistance, development, mental health, longevity and diseases of the X chromosome. The honeybee also is studied for its social instincts and behavioral traits.
INTERNATIONAL EFFORT
After assembling the genome at the Baylor College of Medicine Human Genome Sequencing Center, the center led an analysis team of more than 170 investigators representing nearly 100 research groups from 13 countries.
Researchers deposited the initial assembly in 2004 into the NIH-run public database, GenBank, whose Web site can be found at www.ncbi.nih.gov/Genbank.
GenBank then distributed the sequence data to the European Molecular Biology Laboratory’s Nucleotide Sequence Database (http://www.ebi.ac.uk/embl/index.html) and the DNA Data Bank of Japan (http://www.ddbj.nig.ac.jp).
Additional information about comparative genomics is available at the NIH Web site.
The full text of the press release is available at the NIH Web site.
