LOS ANGELES, Oct. 25
(Xinhua) -- The honeybee, a species that annually contributes billions of
dollars to world's agricultural economy through pollination, originated in
Africa and is evolving in surprising ways, a science consortium reported on
The honeybee, a species that annually
contributes billions of dollars to world's agricultural economy through
pollination, originated in Africa and is evolving in surprising ways, a
science consortium reported on Wednesday.(File Photo)
Honeybees, the premier pollinators on Earth, play a
vital role in world's agriculture. They are also very valuable to scientists as
model for allergic disease, development, gerontology, neuroscience, social
behavior and venom toxicology.
A genome analysis of the honeybee, or Apis mellifera,
has yielded new information about the origins and spread of honeybees throughout
Europe, Asia, and North and South America, the scientists said in the journals
Nature and Science.
The job of mapping the insect's genome enlisted 112
researchers at 63 different institutions that built up the International
Honeybee Genome Consortium. About 10,000 genes were found, 30 percent less than
the fruit fly or mosquito, the scientists said.
To sequence a genome, scientists first extract the
DNA and break it into tiny pieces. Each of those pieces of genetic material is
then sequenced. Lastly, an elaborate computational process puts the pieces back
together in correct order.
The genus Apis is composed of 10 species, nine of
which are confined to Asia. The one exception, A. mellifera, is distributed from
sub-Saharan Africa to Central Asia to Northern Europe, and has more than two
dozens distinct geographical subspecies, the scientists found.
"Our analysis indicates that the honeybee, Apis
mellifera, originated in Africa and spread into Europe by at least two ancient
migrations," said Charles Whitfield, a professor of entomology at the University
of Illinois at Urbana-Champaign who led the study.
"The migrations resulted in two European populations
that are geographically close, but genetically quite different," Whitfield said.
"In fact, the two European populations are more related to honey bees in Africa
than to each other."
The first findings appearing in major scientific
--The honeybee originated in Africa and spread into
Europe by at least two ancient migrations. In the New World, introductions of
the western and northern European subspecies began in North America as early as
--Honeybees have many more genes related to smell,
compared with fruit flies or mosquitoes, but far fewer genes related to taste.
The enhanced number of odorant receptors underlies
the honeybee's remarkable olfactory abilities, including perception of
pheromones, kin recognition signals, and social communication within the hive. A
large number of odorant receptors also allow the bees to find food and
communicate the location of it to other bees.
--Scientists found clues for social cues, a form of
bee pressure that can cause nurse bees to become foragers in response to needs
of the hive. The job shift involves changes in thousands of genes in the
honeybee brain: some genes turn on, while others turn off.
A few "master regulator" genes known to function in
the development of fruit flies have been implicated in regulating the activity
of these thousands of genes. It appears that master regulator genes involved in
nervous-system development in fruit flies are re-used by nature for behavioral
functions in adult honeybees.
The findings could have significant implications for
honeybee breeding and the crucial role these creatures play in farming
worldwide, according to the scientists.