Quantitative Trait Loci Associated with Photoperiodic Response and Stage of Diapause in the Pitcher Plant Mosquito, Wyeomyia smithii

ABSTRACT A wide variety of temperate animals rely on length of day (photoperiodism) to anticipate and prepare for changing seasons by regulating the timing of development, reproduction, dormancy and migration. Although the molecular basis of circadian rhythms regulating daily activities is well-defined, the molecular basis for the photoperiodic regulation of seasonal activities is largely unknown. We use geographic variation in the photoperiodic control of diapause in the pitcher-plant mosquito Wyeomyia smithii to create the first QTL map of photoperiodism in any animal. For critical photoperiod (CPP) we detect QTL that are unique, a QTL that is sex-linked, QTL that overlap with QTL for stage of diapause (SOD), and a QTL that interacts epistatically with the circadian rhythm gene, timeless. Results presented herein confirm earlier studies concluding that CPP is under directional selection over the climatic gradient of North America and that the evolution of CPP is genetically correlated with SOD. Despite epistasis between timeless and a QTL for CPP, timeless is not located within any detectable QTL, indicating that it plays an ancillary role in the evolution of photoperiodism in W. smithii. Lastly, we highlight one region of the genome that includes loci contributing to CPP, SOD and hormonal regulation of development.

Key Words: circadian, diapause, photoperiodism, quantitative trait locus (QTL), timeless

This article has been cited by other articles:

				J. Stehlik, R. Zavodska, K. Shimada, I. Sauman, and V. Kostal Photoperiodic Induction of Diapause Requires Regulated Transcription of timeless in the Larval Brain of Chymomyza costata J Biol Rhythms, April 1, 2008; 23(2): 129 - 139. [Abstract] [PDF]

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