Daylength perception in temperate zones is a critical feature of insect life histories, and leads to developmental changes for resisting unfavourable seasons. The role of the neuroendocrine axis in the photoperiodic response of insects is discussed in relation to the key organs and molecules that are involved. We also discuss the controversial issue of the possible involvement of the circadian clock in photoperiodicity. Drosophila melanogaster has a shallow photoperiodic response that leads to reproductive arrest in adults, yet the unrivalled molecular genetic toolkit available for this model insect should allow the systematic molecular and neurobiological dissection of this complex phenotype.
Bibliographical noteFunding Information:
LS was supported by a doctoral fellowship from the University of Padova. This work was funded by grants from the European Community to R.C. and C.P.K. (6th European Framework. Project EUCLOCK No. 018741). R.C. also thanks the Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR, Project PRIN 2007W3P9ES) and Agenzia Spaziale Italiana (ASI, DCMC Grant).
- Circadian clock
- Clock genes
- Endocrine axis