Altered circadian rhythm, sleep, and rhodopsin 7 -dependent shade preference during diapause in Drosophila melanogaster

• 成果类型: Article
• 署名作者: Meyerhof, Geoff T.; Easwaran, Sreesankar; Bontempo, Angela E.; Montell, Craig; Montell, Denise J.
• 署名单位: University of California System; University of California Santa Barbara
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12098
• DOI: 10.1073/pnas.2400964121
• 发表日期: 2024-07-02
• 关键词: juvenile-hormone regulation; light; temperature; adaptation; trp; cryptochrome; plasticity; physiology; circuits; protein

摘要

To survive adverse environments, many animals enter a dormant state such as hibernation, dauer, or diapause. Various Drosophila species undergo adult reproductive diapause in response to cool temperatures and/or short day - length. While flies are less active during diapause, it is unclear how adverse environmental conditions affect circadian rhythms and sleep. Here we show that in diapause - inducing cool temperatures, Drosophila melanogaster exhibit altered circadian activity profiles, including severely reduced morning activity and an advanced evening activity peak. Consequently, the flies have a single activity peak at a time similar to when nondiapausing flies take a siesta. Temperatures <= 15 degrees C, rather than photoperiod, primarily drive this behavior. At cool temperatures, flies rapidly enter a deep - sleep state that lacks the sleep cycles of flies at higher temperatures and require high levels of stimulation for arousal. Furthermore, we show that at 25 degrees C, flies prefer to siesta in the shade, a preference that is virtually eliminated at 10 degrees C. Resting in the shade is driven by an aversion to blue light that is sensed by Rhodopsin 7 outside of the eyes. Flies at 10 degrees C show neuronal markers of elevated sleep pressure, including increased expression of Bruchpilot and elevated Ca 2+ in the R5 ellipsoid body neurons. Therefore, sleep pressure might overcome blue light aversion. Thus, at the same temperatures that cause reproductive arrest, preserve germline stem cells, and extend lifespan, D. melanogaster are prone to deep sleep and exhibit dramatically altered, yet rhythmic, daily activity patterns.