Thermal tolerance in the keystone species Daphnia magna –a candidate gene and an outlier analysis approach

Research output: Contribution to journalArticle

Authors

  • Mieke Jansen
  • Aurora Geerts
  • Katina I Spanier
  • Carla Denis
  • Luc De Meester

Colleges, School and Institutes

External organisations

  • KULeuven

Abstract

Changes in temperature have occurred throughout Earth’s history. However, current warming trends exacerbated by human activities impose severe and rapid loss of biodiversity. Although understanding the mechanisms orchestrating organismal response to climate change is important, remarkably few studies document their role in nature. This is because only few systems enable the combined analysis of genetic and plastic responses to environmental
change over long time-spans. Here, we characterize genetic and plastic responses to temperature increase in the aquatic keystone grazer Daphnia magna combining a candidate gene and an outlier analysis approach. We capitalize on the short generation time of our species, facilitating experimental evolution, and the production of dormant eggs enabling the analysis of long term response to environmental change through a resurrection ecology
approach. We quantify plasticity in the expression of 35 candidate genes in D. magna populations resurrected from a lake that experienced changes in average temperature over the past century and from experimental populations differing in thermal tolerance isolated from a selection experiment. By measuring expression in multiple genotypes from each of these populations in control and heat treatments we assess plastic responses to extreme temperature
events. By measuring evolutionary changes in gene expression between warm and cold adapted populations we assess evolutionary response to temperature changes. Evolutionary response to temperature increase is also assessed via an outlier analysis using EST-linked microsatellite loci. This study provides the first insights into the role of plasticity and genetic adaptation in orchestrating adaptive responses to environmental change in D. magna.

Details

Original languageEnglish
JournalMolecular Ecology
Publication statusPublished - 1 Feb 2017