Molecular phylogeny of the Cricetinae subfamily based on the mitochondrial cytochrome b and 12S rRNA genes and the nuclear vWF gene

Abstract

Despite some popularity of hamsters as pets and laboratory animals there is no reliable phylogeny of the subfamily Cricetinae available so far. Contradicting views exist not only about the actual number of species but also concerning the validity of several genera. We used partial DNA sequences of two mitochondrial (cytochrome b, 12S rRNA) and one partial nuclear gene (von Willebrand Factor exon 28) to provide a first gene tree of the Cricetinae based on 15 taxa comprising six genera. According to our data, Palaearctic hamsters fall into three distinct phylogenetic groups: Phodopus, Mesocricetus, and Cricetus-related species which evolved during the late Miocene about 7-12 MY ago. Surprisingly, the genus Phodopus, which was previously thought to have appeared during the Pleistocene, forms the oldest clade. The largest number of extant hamster genera is found in a group of Cricetus-related hamsters. The genus Cricetulus itself proved to be not truly monophyletic with Cricetulus migratorius appearing more closely related to Tscherskia, Cricetus, and Allocricetulus. We propose to place the species within a new monotypic genus. Molecular clock calculations are not always in line with the dating of fossil records. DNA based divergence time estimates as well as taxonomic relationships demand a reevaluation of morphological characters previously used to identify fossils and extant hamsters.

Chromosomal evolution in Rodentia

“…Comparative painting and banding within the group permitted the analysis of chromosomal evolution and karyotype relationships within the subfamily resulting in findings that are in broad agreement with molecular data (Neumann et al, 2006). It was determined that Mesocricetus, Tscherskia, Phodopus and Cricetus represent a monophyletic clade (Neumann et al, 2006;Romanenko et al, 2007b). Moreover, different chromosomal rearrangements are characteristic for different lineages.…”

The genetic audiogenic seizure hamster from Salamanca: The GASH:Sal

“…Published studies show that the levels of genetic differentiation in wild golden Syrian hamsters and laboratory strains are low, confirming that all surviving members of the species M. auratus are derived from a limited number of parents [93]. Recently, the analysis of microsatellite loci, used to establish a linkage analysis and to trace patterns of inheritance among populations of wild and laboratory golden hamsters, has shown a reduction in the genetic variability of the population kept in laboratories [96]. This reduction is a consequence of the rupture of Hardy-Weinberg equilibrium in laboratory populations, as well as the effect of inbreeding, because both lead to increased homozygosity in a population.…”

Phylogenetic Relationships and Classification of Didelphid Marsupials, an Extant Radiation of New World Metatherian Mammals

“…Nucleotide sequence data from exon 28 of the von Willebrand factor gene have been analyzed in many previous mammalian phylogenetic studies (e.g., Porter et al, 1996;Huchon et al, 1999;Neumann et al, 2006). The 963 bp fragment that we amplified and sequenced for this study is homologous with a single full-length copy in Monodelphis domestica, where the gene is apparently located on chromosome 8.…”