Mitochondrial DNA variation along an altitudinal gradient in the greater white-toothed shrew, Crocidura russula

Authors


  • This work is part of a research programme on the evolutionary ecology of dispersal and mating strategies, initiated by N Perrin (http://www.unil.ch/izea/research.html#crussula). C. russula is currently our model organism owing to its breeding-system peculiarities, including monogamy and female-biased dispersal. M Ehinger completed her master degree on the topics presented here, in collaboration with P Fontanillas (PhD student) and E Petit (postdoctoral).

N. Perrin. Fax: 41 21 692 41 05; E-mail: nicolas.perrin@ie-zea.unil.ch.

Abstract

The distribution of mitochondrial control region-sequence polymorphism was investigated in 15 populations of Crocidura russula along an altitudinal gradient in western Switzerland. High-altitude populations are smaller, sparser and appear to undergo frequent bottlenecks. Accordingly, they showed a loss of rare haplotypes, but unexpectedly, were less differentiated than lowland populations. Furthermore, the major haplotypes segregated significantly with altitude. The results were inconsistent with a simple model of drift and dispersal. They suggested instead a role for historical patterns of colonization, or, alternatively, present-day selective forces acting on one of the mitochondrial genes involved in metabolic pathways.

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