Insects bugged by 'jumping genes.' (retrotransposons, virus-like DNA fragments, may be useful in controlling insect pests)

Insects bugged by 'jumping genes'

Scientists have discovered that two virus-like agents proliferate in the genetic material of a variety of insect species, raising the prospect of designing new strategies for controlling such pests as cockroaches, gypsy moths and mosquitoes.

The agents are retrotransposons -- DNA fragments that insert copies of themselves into an organism's chromosomes, disrupting any genes into which they happen to land, says Thomas H. Eickbush, an insect molecular biologist at the University of Rochester in New York. In the April 15 PROCEEDINGS of the NATIONAL ACADEMY OF SCIENCES< he and his colleagues report finding two of these fragments, dubbed R1 and R2, in "virtually every insect" they examined.

Because retrotransposons are inherited, scientists could use R1 and R2 to deliver damaging genes into an insect population, Eickbush suggests. The introduced genes might persist indefinitely, providing a means of pest control, he says.

Similar attempts to use other "jumping genes" have proved unsuccessful because researchers have been unable to coax these agents into insects other than fruit flies. However, Eickbush has already identified R1 and R2 in 43 different insect species. He says he plans to try out this novel bug-battling strategy in fruit flies--the insect version of the laboratory rat--before moving on to more destructive pests.