Complex genetic patterns in closely related colonizing invasive species

Ecology and Evolution

Aibin Zhan³  John A. Darling¹  Dan G. Bock³  Anaïs Lacoursière-Roussel²  Hugh J. MacIsaac³ 

[1] National Exposure Research Laboratory, US Environmental Protection Agency, 109 T. W. Alexander Drive, Durham, North Carolina 27711, USA;Department of Biology, McGill University, 1205 Docteur Penfield, Montréal, Québec H3A 1B1, Canada;Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, Ontario N9B 3P4, Canada

关键词: Ciona intestinalis;    genetic complexity;    phylogeography;    population genetics;    selection/local adaptation;    solitary ascidian;   

DOI  :  10.1002/ece3.258

来源: Wiley

【 摘 要 】

Abstract

Anthropogenic activities frequently result in both rapidly changing environments and translocation of species from their native ranges (i.e., biological invasions). Empirical studies suggest that many factors associated with these changes can lead to complex genetic patterns, particularly among invasive populations. However, genetic complexities and factors responsible for them remain uncharacterized in many cases. Here, we explore these issues in the vase tunicate Ciona intestinalis (Ascidiacea: Enterogona: Cionidae), a model species complex, of which spA and spB are rapidly spreading worldwide. We intensively sampled 26 sites (N= 873) from both coasts of North America, and performed phylogenetic and population genetics analyses based on one mitochondrial fragment (cytochrome c oxidase subunit 3–NADH dehydrogenase subunit I, COX3-ND1) and eight nuclear microsatellites. Our analyses revealed extremely complex genetic patterns in both species on both coasts. We detected a contrasting pattern based on the mitochondrial marker: two major genetic groups in C. intestinalis spA on the west coast versus no significant geographic structure in C. intestinalis spB on the east coast. For both species, geo-graphically distant populations often showed high microsatellite-based genetic affinities whereas neighboring ones often did not. In addition, mitochondrial and nuclear markers provided largely inconsistent genetic patterns. Multiple factors, including random genetic drift associated with demographic changes, rapid selection due to strong local adaptation, and varying propensity for human-mediated propagule dispersal could be responsible for the observed genetic complexities.

【 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.