Isolation and characterization of drosophila mutants with abnormal temperature-preference behavior

Abstract

Thermosensation is one of the important and basic sensation systems such as visual, olfactory and mechenosensory system in organisms for survival in the environment, but little is known about it. The mechanism of thermosensation at the molecular level has recently been elucidated in C. elegans to a certain degree, but it seems that Drosophila is still an attractive model organism to study thermosensation because of its central nerve system which is absent in C.elegans. So in Drosophila P-insertion libraries, thirteen thousands independent lines were tested for thermomutants which are considered to be defective in thermosensation or thermoregulation using radial and linear temperature gradient and then fifty seven candidates were selected as thermomutants. Flanking sequence of each insertion of those mutants was recovered, and possibly affected genes were predicted through database search. Among them, some outstanding candidates were investigated for further characterization including RNA binding protein with a homologue of bruno-like 5, a protein similar to inositol hexakisphosphatase 6, hydrophobic molecule transfer protein and Drosophila homologue of $dopamine-\beta -hydroxylase$. These candidates showed the distinct temperature-preference such as hypersensitive, hyposensitive, thermophilic and cryophilic phenotype. X-gal staining patterns revealed that some of them were expressed in central nerve system (CNS), cuticle and antenna disc respectively. Taken together, these data suggest that they would contribute a wide range of diverse process in thermosensation in Drosophila. More detailed research following this study will be a good initiative to understand the thermosense system.