Pliocene and Pleistocene diversification and multiple refugia in a Eurasian shrew (Crocidura suaveolens group)

Abstract

We sequenced 998 base pairs (bp) of mitochondrial DNA cytochrome b and 799 bp of nuclear gene BRCA1 in the Lesser white-toothed shrew (Crocidura suaveolens group) over its geographic range from Portugal to Japan. The aims of the study were to identify the main clades within the group and respective refugia resulting from Pleistocene glaciations. Analyses revealed the Asian lesser white-toothed shrew (C. shantungensis) as the basal clade, followed by a major branch of C. suaveolens, subdivided sensu stricto into six clades, which split-up in the Upper Pliocene and Lower Pleistocene (1.9-0.9 Myr). The largest clade, occurring over a huge range from east Europe to Mongolia, shows evidence of population expansion after a bottleneck. West European clades originated from Iberian and Italo-Balkanic refugia. In the Near East, three clades evolved in an apparent hotspot of refugia (west Turkey, south-west and south-east of the Caucasus). Most clades include specimens of diVerent morphotypes and the validity of many taxa in the C. suaveolens group has to be re-evaluated. 

Cytogenetic and Molecular Relationships between Zarudny's Rock Shrew (Crocidura zarudnyi; Mammalia: Soricomorpha) and Eurasian Taxa

“…In all phylogenetic analyses, 6 well-defined clades were found. The 1st included the samples of the C. suaveolens group (Asian lesser white-toothed shrew [C. shantungensis] and C. suaveolens; for more details about the systematics of this group, see Dubey et al [2006]) and C. zarudnyi, 2N ¼ 40, FN ¼ 50, which is the sister taxon to the latter species; this was ; bootstrap values of 90% and 63% for maximum likelihood and maximum parsimony, and Bayesian posterior probablity of 0.8). The last clade included the samples of C. olivieri and C. viaria (2N ¼ 50, FN ¼ 66; maximum-likelihood and maximum-parsimony bootstrap values of 100%, and Bayesian posterior probability of 1.0).…”

Molecular phylogenetics reveals Messinian, Pliocene, and Pleistocene colonizations of islands by North African shrews

“…Most of the shrews analyzed in this study are from the IZEA collection (University of Lausanne, Switzerland). The two sequences of Crocidura suaveolens were taken from Dubey et al (2006). DNA extraction was carried out using a QIAamp DNA Mini Kit (Qiagen).…”

“…DNA extraction was carried out using a QIAamp DNA Mini Kit (Qiagen). Double-stranded DNA amplifications of cytochrome b gene were performed with the primer pairs L14841/C4, C1/C2, C3/H15915, and L14841/H15915 (Irwin et al, 1991;Dubey et al, 2006). Amplification conditions consisted of 35 thermal cycles of 30 s denaturation (60 s for the set L14841/H15915) at 94°C, 45 s annealing (60 s, L14841/H15915) at 50°C, and 60 s (120 s, L14841/ H15915) extension at 72°C.…”

“…Estimation of the divergence time from the molecular data was performed according to a calibration developed previously for the Soricidae by Fumagalli et al (1999), and that allowed fully coherent results in a biogeographic point of view (see, e.g., Vogel et al, 2003;Brändli et al, 2006;Cosson et al, 2005;Dubey et al, 2006Dubey et al, , 2007a. This calibration is based on an estimate of 20 million years for the split between Crocidurinae and Soricinae shrews, and it was developed considering the cytochrome b sequence divergences based on third position transversions, with a rate of 1.36%/Myr (95% confidence interval: 1.08-1.64%/ Myr).…”

About the presence of Crocidura suaveolens group (Soricomorpha, Soricidae) on Astipalaia Island (Dodecanese, Greece)

“…r. gueldenstaedti Pallas, 1811, from Turkey, proposed as incertae sedis by Catzeflis et al (1985), was more recently placed to C. suaveolens group, as a separate species (Zaitsev, 1991;Bannikova et al, 2006;Vogel et al, 2003) or a subspecies of C. suaveolens (Hofmann, 1996;Dubey et al, 2006;2007). On the basis of the genetics data, this taxon can be considered as occurring in Turkey, Crete, Georgia (Dubey et al, 2006), Israel, western Syria, and western Iran (Dubey et al, 2007).…”