Bee-Killing Parasite's Genome Sequenced
O'Brien June 5, 2009
Agricultural Research Service
(ARS) scientists have sequenced the genome of an invasive parasite called
Nosema ceranae that can kill honey bees and is one of the many suspects
in the mysterious ailment known as colony collapse disorder (CCD).
(Judy) Chen and R. Scott Cornman also have nearly completed sequencing the
genome of Nosema apis, a native "cousin" of the parasite.
The scientists are using genetic tools and microscopic analysis at the
Bee Research Laboratory (BRL) in Beltsville, Md., to examine the two
parasites suspected as a partial cause of CCD. They are working with BRL
Zhao of the
Molecular Plant Pathology Laboratory in Beltsville, and researchers from
the University of Maryland,
Columbia University, and
454 Life Sciences of Branford, Conn.
In 2006, CCD began devastating commercial beekeeping operations, with
some beekeepers reporting losses of up to 90 percent. Researchers believe CCD
may be the result of a combination of pathogens, parasites and stress factors,
but the cause remains elusive. At stake are honey bees that add up to $15
billion in value to crops in the United States.
Nosema is a fungus-related microbe that produces spores that
bees consume when they forage. Infection spreads from the bees' digestive tract
to other tissues. Within weeks, colonies are either wiped out or lose much of
their strength. N. apis was the leading cause of microsporidia
infections among domestic bee colonies until recently, when N. ceranae
jumped from Asian honey bees to the European honey bees used commercially in
the United States.
Sequencing the genomes should help scientists figure out how N.
ceranae became dominant, trace its migration patterns, help resolve how the
microbes spread infection, and develop diagnostic tests and treatments.
report on the work was recently published in the journal PLOS Pathogens.
ARS is the principal intramural scientific research agency in the
U.S. Department of Agriculture.