Mitochondrial DNA reveals hidden diversity and an ancestral lineage of the bank vole in the Italian peninsula

Abstract

The Italian Peninsula was one of the main refugia in southern Europe during the climatic oscillations of the Pleistocene, and was considered a 'hotspot' of biodiversity. A number of phylogeographic analyses identified highly divergent lineages in Italy that apparently did not contribute to the post-glacial re-colonization of Europe, supporting the existence of refugia within refugia in the southern-most part of Italy. For the bank vole Myodes glareolus, genetic analyses highlighted a low variability for this species on the Italian peninsula, suggesting that cryptic refugia of central Europe were the main source of postglacial re-colonization in Europe. In this work, we analysed the mtDNA phylogeography of M. glareolus with a special emphasis on the Italian refugium. We extended previous analyses by including new sequences from a wider range of samples across the Italian peninsula. Our results suggest a high mitochondrial diversity of the bank vole in Italy and support the existence of an ancient and deeply divergent population in the Calabria region. This population did not participate to the recent re-colonization of Italy while we highlight the possible occurrence of multiple and more recent colonization events between Europe and Italy. The phylogeographic pattern observed in Italy appears compatible with refugia-within-refugia scenario. © 2011 The Zoological Society of London

Mammal endemism In Italy: A review

“…Recent molecular data strongly support that the Calabrian populations of M. glareolus may represent a distinct species (Colangelo et al 2012a). This interpretation is supported by its phylogenetic position and mitochondrial DNA distinctiveness respect to all the other M. glareolus populations distributed in Europe and central and northern Italy (Colangelo et al 2012a, Filipi et al 2015. The available name for the Calabrian population would be Myodes hallucalis (Thomas, 1906) (Gippoliti, 2013).…”

“…The available name for the Calabrian population would be Myodes hallucalis (Thomas, 1906) (Gippoliti, 2013). Molecular clock suggests a divergence of the Calabrian lineage that can be set around 0.79 MYA (Colangelo et al 2012a).…”

Higher genetic diversity on mountain tops: the role of historical and contemporary processes in shaping genetic variation in the bank vole

“…This small rodent has a broad European distribution, from the British Isles and central-western Europe to Scandinavia and western Russia (Cook, Runck & Conroy, 2004). Given its wide distribution, the bank vole has been used to identify main European glacial refugia and pathways of postglacial recolonization (Deffontaine et al, 2005;Kotl ık et al, 2006;Colangelo et al, 2012;Filipi et al, 2015). Given its wide distribution, the bank vole has been used to identify main European glacial refugia and pathways of postglacial recolonization (Deffontaine et al, 2005;Kotl ık et al, 2006;Colangelo et al, 2012;Filipi et al, 2015).…”

Relaxed functional constraints on triplicate α-globin gene in the bank vole suggest a different evolutionary history from other rodents

“…Given the ubiquity of gene duplication and loss in the mammalian a-globin gene family , it is plausible that bank vole HBA-T3 represents an independent duplication from those in Peromyscus and Rattus. The fact that the Calabrian bank vole (a likely sibling species to C. glareolus; Colangelo et al, 2012) and the grey redbacked vole (C. rufocanus) both share an orthologous HBA-T3 gene with the bank vole (Supplementary Figure S1) shows its origin predates the split between the ancestors of the bank vole and grey redbacked vole. The bank vole and grey red-backed vole belong to different major subdivisions in the genus (Cook et al, 2004), and the duplication thus might be shared by all Clethrionomys species.…”

“…In addition, one specimen of bank vole from Calabria, Italy (a likely sibling species to C. glareolus; Colangelo et al, 2012), and one grey red-backed vole C. rufocanus from Norway were sampled. Blood was obtained by cardiac puncture from killed bank voles and the heparinised cells were collected by centrifugation (3000 r.p.m.…”