Abstract
Summary Here, we describe a targeted reverse genetic screen for thermal nociception genes of Drosophila larvae. Using laser capture microdissection and microarray analyses of nociceptive and non-nociceptive neurons we identified 275 nociceptor-enriched genes. We then tested the function of the enriched genes with nociceptor-specific RNAi and thermal nociception assays. Tissue specific RNAi targeted against 14 genes caused insensitive thermal nociception while targeting of 22 genes caused hypersensitive thermal nociception. Previously uncategorized genes were named for heat resistance (ie. boilerman, fire dancer, oven mitt, trivet, thawb and bunker gear) or heat sensitivity (firelighter, black match, eucalyptus, primacord, jet fuel, detonator, gasoline, smoke alarm, and jetboil). Insensitive nociception phenotypes were often associated with severely reduced branching of nociceptor neurites and hyperbranched dendrites were seen in two of the hypersensitive cases. Many genes that we identified were not isolated in a prior genome-wide screen, and are evolutionarily conserved in mammals.
Highlights
Laser capture microarray analyses identify 275 nociceptor-enriched genes
Nociceptor-specific RNAi screens implicate 36 genes in thermal nociception
The screens identify genes that are newly implicated in nociception signaling
Homologues of nociception genes are enriched in mammalian nociceptors
eTOC Blurb Using tissue-specific microarray analyses and nociceptor-specific RNAi screens in Drosophila, Honjo et al. identify genes that show enriched expression in nociceptors and with genetic screens find those that are functionally important for thermal nociception. Many of these genes are evolutionarily conserved and had previously unknown functions in nociception.