Abstract
Temperature sensation guides animals to avoid temperature extremes and to seek their optimal temperatures. The larval stage of Drosophila development has a dramatic effect on temperature preference. While early-stage Drosophila larvae pursue a warm temperature, late-stage larvae seek a significantly lower temperature. Previous studies suggest that this transition depends on multiple rhodopsins at the late larval stage. Here, we show that early-stage larvae, in which dorsal organ cool cells (DOCCs) are functionally blocked, exhibit similar cool preference to that of wild type late-stage larvae. The molecular thermoreceptors in DOCCs are formed by three members of the Ionotropic Receptor (IR) family, IR21a, IR93a, and IR25a. Early-stage larvae of each Ir mutant pursue a cool temperature, similar to that of wild type late-stage larvae. At the late larval stage, DOCCs express decreased IR proteins and exhibit reduced cool responses. Importantly, late-stage larvae that overexpress IR21a, IR93a, and IR25a in DOCCs exhibit similar warm preference to that of wild type early-stage larvae. These data suggest that IR21a, IR93a, and IR25a in DOCCs navigate early-stage larvae to avoid cool temperatures and the reduction of these IR proteins in DOCCs results in animals remaining in cool regions during the late larval stage. Together with previous studies, we conclude that multiple temperature-sensing systems are regulated for the transition of temperature preference in fruit fly larvae.
Highlights
Temperature sensation is vital for animals to avoid extreme temperatures and to seek optimal temperatures to survive, mate, and reproduce
Drosophila larvae seek a lower temperature during the late third instar To understand Drosophila larval thermotactic behaviors, we set up a temperature gradient from 13–31 ̊C (S1 Fig)
Drosophila larvae preferred a lower temperature of 18–20 ̊C during the late third instar (120 hr AEL) (Fig 1A and 1C)
Summary
Temperature sensation is vital for animals to avoid extreme temperatures and to seek optimal temperatures to survive, mate, and reproduce. Previous studies show that this transition depends on multiple rhodopsins (including Rh5 and Rh6), the phospholipase C (PLC) signaling pathway (including Gq and PLC), and the transient receptor potential channel TRPA1 [9]. These genes are expressed at the late third instar and are required to select low temperatures. Mutants of these genes pursue a similar temperature of 24 ̊C at both early and late third instar and do not exhibit the transition of temperature preference observed in wild type [9]. We focus on low-temperature sensing systems and investigate whether and how low-temperature sensing pathways contribute to the transition of temperature preference in Drosophila larvae
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
