Adaptation to a seasonally varying environment: a strong latitudinal cline in reproductive diapause combined with high gene flow in Drosophila montana

Ecology and Evolution

Venera I. Tyukmaeva¹  Tiina S. Salminen¹  Maaria Kankare¹  K. Emily Knott¹ 

[1] Department of Biological and Environmental Science, Centre of Excellence in Evolutionary Research, P.O. Box 35, 40014 University of Jyväskylä, Finland

关键词: Critical day length;    gene flow;    genetic variation;    microsatellites;    population structure;    seasonal adaptation;   

DOI  :  10.1002/ece3.14

来源: Wiley

【 摘 要 】

Abstract

Adaptation to seasonal changes in the northern hemisphere includes an ability to predict the forthcoming cold season from gradual changes in environmental cues early enough to prepare for the harsh winter conditions. The magnitude and speed of changes in these cues vary between the latitudes, which induces strong selection pressures for local adaptation.

We studied adaptation to seasonal changes in Drosophila montana, a northern maltfly, by defining the photoperiodic conditions leading to adult reproductive diapause along a latitudinal cline in Finland and by measuring genetic differentiation and the amount of gene flow between the sampling sites with microsatellites. Our data revealed a clear correlation between the latitude and the critical day length (CDL), in which half of the females of different cline populations enter photoperiodic reproductive diapause. There was no sign of limited gene flow between the cline populations, even though these populations showed isolation by distance. Our results show that local adaptation may occur even in the presence of high gene flow, when selection for locally adaptive life-history traits is strong. A wide range of variation in the CDLs of the fly strains within and between the cline populations may be partly due to gene flow and partly due to the opposing selection pressures for fly reproduction and overwinter survival. This variation in the timing of diapause will enhance populations’ survival over the years that differ in the severity of the winter and in the length of the warm period and may also help them respond to long-term changes in environmental conditions.

【 授权许可】

CC BY-NC   
© 2011 The Authors. MicrobiologyOpen published by Blackwell Publishing Ltd.

Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.