Interaction of light regimes and circadian clocks modulate timing of pre-adult developmental events in Drosophila

Abstract

BackgroundCircadian clocks have been postulated to regulate development time in several species of insects including fruit flies Drosophila melanogaster. Previously we have reported that selection for faster pre-adult development reduces development time (by ~19 h or ~11%) and clock period (by ~0.5 h), suggesting a role of circadian clocks in the regulation of development time in D. melanogaster. We reasoned that these faster developing flies could serve as a model to study stage-specific interaction of circadian clocks and developmental events with the environmental light/dark (LD) conditions. We assayed the duration of three pre-adult stages in the faster developing (FD) and control (BD) populations under a variety of light regimes that are known to modulate circadian clocks and pre-adult development time of Drosophila to examine the role of circadian clocks in the timing of pre-adult developmental stages.ResultsWe find that the duration of pre-adult stages was shorter under constant light (LL) and short period light (L)/dark (D) cycles (L:D = 10:10 h; T20) compared to the standard 24 h day (L:D = 12:12 h; T24), long LD cycles (L:D = 14:14 h; T28) and constant darkness (DD). The difference in the duration of pre-adult stages between the FD and BD populations was significantly smaller under the three LD cycles and LL compared to DD, possibly due to the fact that clocks of both FD and BD flies are driven at the same pace in the three LD regimes owing to circadian entrainment, or are rendered dysfunctional under LL.ConclusionsThese results suggest that interaction between light regimes and circadian clocks regulate the duration of pre-adult developmental stages in fruit flies D. melanogaster.

Energy demand and the context-dependent effects of genetic interactions underlying metabolism

“…In many insects, including Drosophila, endogeneous circadian clocks influence the timing of developmental hallmarks (e.g., pupation, eclosion; Kyriacou et al 1990). Circadian rhythms result in "gated" periods of development, which can be entrained by diurnal variation in photoperiod to further increase the synchronicity of discrete developmental events (e.g., pupation, eclosion; Ashmore andSehgal 2003, Nijhout et al 2010;Yadav et al 2014). Flies can develop fastest in constant light, absent of photoperiodic entrainment (Paranjpe et al 2005).…”

“…; Yadav et al. ). Flies can develop fastest in constant light, absent of photoperiodic entrainment (Paranjpe et al.…”

Localization of quantitative trait loci for diapause and other photoperiodically regulated life history traits important in adaptation to seasonally varying environments

“…; Yadav et al . ). Overall, information on the photoperiodic control of insects’ life cycles, as well as on trade‐offs and correlations between the traits, is of utmost importance for understanding adaptation processes occurring in insect populations living in environments with high seasonal variation.…”

“…; Yadav et al . ) and to show plasticity also in response to different temperatures (e.g. Vesala & Hoikkala ).…”

“…; Yadav et al . ) and juvenile body weight (Hahn & Denlinger ; Salminen et al . ), have been found to be at least partly regulated by photoperiod and temperature, and the effects of diapause may not always be easy to distinguish from the direct effects of these cues.…”