Temperature sensation in Drosophila

Abstract

Animals use thermosensory systems to achieve optimal temperatures for growth and reproduction and to avoid damaging extremes. Thermoregulation is particularly challenging for small animals like the fruit fly Drosophila melanogaster, whose body temperature rapidly changes in response to environmental temperature fluctuation. Recent work has uncovered some of the key molecules mediating fly thermosensation, including the Transient Receptor Potential (TRP) channels TRPA1 and Painless, and the Gustatory Receptor Gr28b, an unanticipated thermosensory regulator normally associated with a different sensory modality. There is also evidence the Drosophila phototransduction cascade may have some role in thermosensory responses. Together, the fly’s diverse thermosensory molecules act in an array of functionally distinct thermosensory neurons to drive a suite of complex, and often exceptionally thermosensitive, behaviors.

Thermosensation and the TRPV channel in Rhodnius prolixus

“…melanogaster, three channels belonging to the TRPA subfamily are related to thermosensation (dTRPA1, painless and pyrexia) and mediate responses to moderate and high temperatures (Dhaka et al, 2006;Hamada et al, 2008;Barbagallo and Garrity, 2015), fact that has also been observed recently in other insect species (Kim et al 2015). painless and pyrexia channels are present in other insect species (like Bombyx mori, Tribolium castaneum, Apis mellifera, Nasonia vitripennis and Pediculus humanus), suggesting that channels for the detection of noxious temperatures are conserved among different insect taxa (Matsuura et al, 2009).…”

Drosophila Chemoreceptors: A Molecular Interface Between the Chemical World and the Brain

“…A number of Trps are expressed in taste and olfactory organs of the fly [7, 85]. Two of them, TrpA1 and Painless, act in thermosensation [126] but are also expressed in taste organs. TRPA1 is required for the response to noxious electrophiles, and is activated by electrophiles when expressed in Xenopus oocytes [127].…”

Insect TRP channels as targets for insecticides and repellents

“…36,37) Drosophila have four TRPA channels-TRPA1, Painless (Pain), Pyrexia (Pyx) and water witch (Wtrw). With the exception of Wtrw all of these are involved in thermosensation.…”

“…Although TRPA1 is involved in the noxious heat response, this response also involves the other two thermoTRPs-Pain, which has a temperature activation threshold of 39 to 42°C, and Pyx, which opens at 46°C, but the individual roles of the three channels are unclear. 13,36) TRPA1 is likewise required for avoidance of high-intensity light by larvae, by an unknown mechanism that may also involve a gustatory receptor.…”