Nanda-Hamner Curves Show Huge Latitudinal Variation but No Circadian Components in Drosophila Montana Photoperiodism
Lankinen, P. (2021). Nanda-Hamner Curves Show Huge Latitudinal Variation but No Circadian Components in Drosophila Montana Photoperiodism. Journal of Biological Rhythms, 36(3), 226-238. https://doi.org/10.1177/0748730421997265
Published inJournal of Biological Rhythms
© 2021 the Authors
Insect species with a wide distribution offer a great opportunity to trace latitudinal variation in the photoperiodic regulation of traits important in reproduction and stress tolerances. We measured this variation in the photoperiodic time-measuring system underlying reproductive diapause in Drosophila montana, using a Nanda-Hamner (NH) protocol. None of the study strains showed diel rhythmicity in female diapause proportions under a constant day length (12 h) and varying night lengths in photoperiods ranging from 16 to 84 h at 16°C. In the northernmost strains (above 55°N), nearly all females entered diapause under all photoperiods and about half of them even in continuous darkness, while the females of the southern strains showed high diapause proportions only in the circadian 24 h photoperiod. Significant correlation between the strains’ mean diapause proportions in ≥ 24 h photoperiods and critical day length (CDL; half of the females enter diapause) suggests at least partial causal connection between the traits. Interestingly, females of the northern strains entered diapause even in ≤ 24 h photoperiods, where the night length was shorter than their critical night length (24 h - CDL), but where the females experienced a higher number of Light:Dark cycles than in 24 h photoperiods. NH experiments, performed on the control and selection lines in our previous selection experiment, and completed here, gave similar results and confirmed that selection for shorter, southern-type CDL decreases female diapausing rate in non-circadian photoperiods. Overall, our study shows that D. montana females measure night length quantitatively, that the photoperiodic counter may play a prominent but slightly different role in extra short and extra long photoperiods and that northern strains show high stability against perturbations in the photoperiod length and in the presence of LD cycles. These features are best explained by the quantitative versions of the damped external coincidence model. ...
ISSN Search the Publication Forum0748-7304
Publication in research information system
MetadataShow full item record
Additional information about fundingThe author(s) received no financial support for the research, authorship, and/or publication of this article.
Showing items with similar title or keywords.
Plasticity in Photoperiodism : Drosophila montana Females Have a Life-Long Ability to Switch From Reproduction to Diapause Lankinen, Pekka; Kastally, Chedly; Hoikkala, Anneli (SAGE Publications, 2022)Photoperiodic reproductive diapause is an essential part of female life cycle in several insect species living on high latitudes, where overwintering in reproductive stage involves high risks for survival and progeny ...
Selection for reproduction under short photoperiods changes diapause-associated traits and induces widespread genomic divergence Kauranen, Hannele; Kinnunen, Johanna; Hiillos, Anna-Lotta; Lankinen, Pekka; Hopkins, David; Wiberg, R. Axel W; Ritchie, Michael G.; Hoikkala, Anneli (Company of Biologists, 2019)The incidence of reproductive diapause is a critical aspect of life history in overwintering insects from temperate regions. Much has been learned about the timing, physiology and genetics of diapause in a range of insects, ...
Adaptation and ecological speciation in seasonally varying environments at high latitudes : Drosophila virilis group Hoikkala, Anneli; Poikela, Noora (Informa UK Limited, 2022)Living in high latitudes and altitudes sets specific requirements on species’ ability to forecast seasonal changes and to respond to them in an appropriate way. Adaptation into diverse environmental conditions can also ...
Latitudinal clines in the timing and temperature‐sensitivity of photoperiodic reproductive diapause in Drosophila montana Tyukmaeva, Venera; Lankinen, Pekka; Kinnunen, Johanna; Kauranen, Hannele; Hoikkala, Anneli (John Wiley & Sons, 2020)Reproductive diapause is a primary mechanism used by arthropods to synchronize their life cycle with seasonal changes in temperate regions. Our study species, Drosophila montana, represents the northern insect species where ...
Direct and correlated responses to bi-directional selection on pre-adult development time in Drosophila montana Kauranen, Hannele; Kinnunen, Johanna; Hopkins, David; Hoikkala, Anneli (Elsevier Ltd., 2019)Selection experiments offer an efficient way to study the evolvability of traits that play an important role in insects’ reproduction and/or survival and to trace correlations and trade-offs between them. We have exercised ...