Cornell University scientists have uncovered a set of neurons in fruit flies that shut down in cold temperatures and slow reproduction, a system conserved in many insects, including mosquitoes, which could provide a target for pest control.
The study, published February 16 in the journal Current Biology, is a step toward understanding how a fly’s brain contributes to sensing the cold and limiting reproduction. Insects and animals, including many mammals, curb reproduction in the winter to protect their newborns from being exposed to harsh winter conditions.
The study has public health and agricultural implications, as tapping into environmentally dependent mechanisms that influence reproduction in mosquitoes and crop pests may offer new control strategies. Mosquitoes act as reservoirs for the malaria-causing Plasmodium falciparum parasite, which spend the winter inside them.
In the study, researchers conducted genetic screens and identified a subset of circadian neurons in the fly brain. These circadian neurons are important for sensing and responding to such environmental cues as light and cold and for keeping time in the brain, but they are not well understood.
While light may have some effect on reproduction, cold temperatures dominate light in controlling reproduction. In experiments where fruit flies were exposed to long days and cold temperatures, the rate of egg production still slowed down.
In future work, the scientists plan to generate mutant mosquitos for the AstC peptide and its receptor to further understand their roles in regulating egg production in mosquitos. If modifying the AstC receptor reduces reproduction, it could become a target for chemical intervention that could suppress mosquito and agricultural pest populations.
The study was supported by the National Institutes of Health.