The Aroian lab at UCSD uses C. elegans to study Bt (bacillus
thuringiensis). Bt is related to a species of bacteria that
causes food poisoning and also to the bacterium that causes anthrax (bacillus
anthracis). Bt kills only very specific species of insects.
Many organic farmers have used Bt for over 50 years as a pesticide
to control insects. Bt is also used to control mosquitoes, and
other insects that bite and spread disease. And now, genes from Bt
is used to modify plants so that the plants produce the Bt toxins
and kill insects that try to eat them without any external spraying.
So with 50 yrs of use, you'd think we've got everything figured out
about Bt. But the truth is, we don't know much. Most importantly,
we don't know how it works. Some would argue, why bother knowing how it
works if it's been working for the past 50 yrs. True, but then there is
the problem of resistance. What if insects turn resistant to Bt
like many bacterium have turned resistant to antibiotics?
For every single synthetic pesticide that is in use today, there are
species of insects that are resistant to it. Many of the more powerful
synthetic pesticides have been or will be taken off the market due to
health and environmental hazards. There have been reports of 2 species
in the field that are resistant to Bt, there will be more. So
in the hopes of preventing this, labs like the Aroian lab are trying to
figure out how Bt works on a molecular level and maybe someday
find out a way to prevent resistance in insects.