Evolutionary mechanisms of habitat invasions, using the copepod Eurytemora affinis as a model system

Evolutionary Applications

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关键词: antagonistic pleiotropy;    balancing selection;    biological invasions;    crustacea;    evolutionary trade‐offs;    immunohistochemistry;    osmoregulation;    phenotypic plasticity;   

DOI  :  10.1111/eva.12334

来源: Wiley

【 摘 要 】

Abstract

The study of the copepod Eurytemora affinis has provided unprecedented insights into mechanisms of invasive success. In this invited review, I summarize a subset of work from my laboratory to highlight key insights gained from studying E. affinis as a model system. Invasive species with brackish origins are overrepresented in freshwater habitats. The copepod E. affinis is an example of such a brackish invader, and has invaded freshwater habitats multiple times independently in recent years. These invasions were accompanied by the evolution of physiological tolerance and plasticity, increased body fluid regulation, and evolutionary shifts in ion transporter (V-type H⁺ ATPase, Na⁺, K⁺-ATPase) activity and expression. These evolutionary changes occurred in parallel across independent invasions in nature and in laboratory selection experiments. Selection appears to act on standing genetic variation during invasions, and maintenance of this variation is likely facilitated through ‘beneficial reversal of dominance’ in salinity tolerance across habitats. Expression of critical ion transporters is localized in newly discovered Crusalis leg organs. Increased freshwater tolerance is accompanied by costs to development time and greater requirements for food. High-food concentration increases low-salinity tolerance, allowing saline populations to invade freshwater habitats. Mechanisms observed here likely have relevance for other taxa undergoing fundamental niche expansions.

【 授权许可】

CC BY   
© 2015 The Author. Evolutionary Applications published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.