TY - JOUR
T1 - Evolution of photoperiodic time measurement is independent of the circadian clock in the pitcher-plant mosquito, Wyeomyia smithii
AU - Emerson, Kevin J.
AU - Dake, Sabrina J.
AU - Bradshaw, William E.
AU - Holzapfel, Christina M.
N1 - Funding Information:
Acknowledgments We thank A. Letaw for discussion, A. Letaw and two anonymous reviewers for their comments on previous versions of this paper, and B. Kolaczkowski for valuable discussions on likelihood methods. All work presented here complied with the ‘‘Principles of animal care,’’ publication No. 86-23 of the National Institute of Health, and also with current laws of the United States, where these experiment were performed. This work was made possible by generous support from the National Science Foundation through grants DEB-0412573, IOB-0445710 and IOB-0520799 (REU supplement for SJD) to WEB, and the National Science Foundation and National Institutes of Health through training grants DGE-0504727 and 5-T32-GMO7413 to KJE.
PY - 2009/4
Y1 - 2009/4
N2 - For over 70 years, researchers have debated whether the ability to use day length as a cue for the timing of seasonal events (photoperiodism) is related to the endogenous circadian clock that regulates the timing of daily events. Models of photoperiodism include two components: (1) a photoperiodic timer that measures the length of the day, and (2) a photoperiodic counter that elicits the downstream photoperiodic response after a threshold number of days has been counted. Herein, we show that there is no geographical pattern of genetic association between the expression of the circadian clock and the photoperiodic timer or counter. We conclude that the photoperiodic timer and counter have evolved independently of the circadian clock in the pitcher-plant mosquito Wyeomyia smithii and hence, the evolutionary modification of photoperiodism throughout the range of W. smithii has not been causally mediated by a corresponding evolution of the circadian clock.
AB - For over 70 years, researchers have debated whether the ability to use day length as a cue for the timing of seasonal events (photoperiodism) is related to the endogenous circadian clock that regulates the timing of daily events. Models of photoperiodism include two components: (1) a photoperiodic timer that measures the length of the day, and (2) a photoperiodic counter that elicits the downstream photoperiodic response after a threshold number of days has been counted. Herein, we show that there is no geographical pattern of genetic association between the expression of the circadian clock and the photoperiodic timer or counter. We conclude that the photoperiodic timer and counter have evolved independently of the circadian clock in the pitcher-plant mosquito Wyeomyia smithii and hence, the evolutionary modification of photoperiodism throughout the range of W. smithii has not been causally mediated by a corresponding evolution of the circadian clock.
KW - Biological clocks
KW - Diapause
KW - Geographic variation
KW - Photoperiodism
KW - Seasonality
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U2 - 10.1007/s00359-009-0416-9
DO - 10.1007/s00359-009-0416-9
M3 - Article
C2 - 19190920
AN - SCOPUS:64149086155
SN - 0340-7594
VL - 195
SP - 385
EP - 391
JO - Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology
JF - Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology
IS - 4
ER -