Vinegar Fly Gene Confers
MELBOURNE, Australia, September 27, 2002 (ENS) -
Scientists have discovered a single gene that gives vinegar flies
resistance to a wide range of pesticides, including the banned DDT. This
species is rarely targeted with pesticides, and many of the chemicals it
is resistant to, it has never been exposed to before.
"This is a warning that we may need to
rethink our overall strategies to control insect pests," says University
of Melbourne geneticist, Dr. Phil Batterham. He serves as program leader
for the Chemical Stress Program within the Centre for Environmental Stress
and Adaptation Research (CESAR), a special research centre that includes
researchers from the Universities of Melbourne, La Trobe and Monash.
"The fact that a single mutation can
confer resistance to DDT and a range of unrelated pesticides, even to
those the species has never encountered, reveals new risks and costs to
the chemical control of pest insects," Dr. Batterham said.
The Drosophila resistance gene, named
Cyp6g1, is part of a large family of genes called the Cytochrome P450
genes that are found in many species, including humans.
The gene has persisted rather than
disappearing as the use of DDT around the world has declined since it was
banned in 1972 in the United States.
"Unless we reassess our current methods
of pest management, our future options for control may become severely
restricted," Dr. Batterham warned. "If this mutation was found on a pest
insect, many options for the chemical control of that insect would have
Species will normally lose mutations that
protected it against a particular pesticide once that pesticide ceases to
be used. This is because, in the absence of the pesticide, the mutation
suddenly confers a disadvantage.
In this case, the vinegar fly has
maintained the resistance gene. The mutation does not confer any
disadvantage, so it persists in the fly population.
"This highlights more than ever that what
we do today to control pests could irreversibly change the gene pool of
that species," says Batterham.
"This research showed how easy it is for
a single mutation to have such a diverse impact. A similar mutation in a
pest species could have devastating consequences," he says.
The primary research was done by Dr. Phil
Daborn, a former Ph.D. student under Dr. Batterham and Professor John
McKenzie at the University of Melbourne. It took place in the laboratory
of Professor Richard French-Constant at the University of Bath. Current
University of Melbourne students Michael Bogwitz and Trent Perry
contributed. Other collaborators include Professor Tom Wilson at Colorado
State University and Dr. Rene Feyereisen at Centre de Recherches d'Antibes,
The research is published under the
title, "Why Bugs Resist Insecticides," in the current edition of the
journal "Science," a publication of the American Association for the
Advancement of Science.
Copyright Environment News Service (ENS) 2002. All Rights Reserved.