RESUMO
The Egyptian weasel (Mustela subpalmata) is a small mustelid with a distribution restricted to the lower Nile Valley and the Nile Delta. Traditionally considered a subspecies of the least weasel (M. nivalis), it is currently recognized as a separate species based on morphology. Here we present the first genetic assessment of the taxonomic status of the Egyptian weasel by comparing mitochondrial DNA (Cytochrome b gene and control region) sequences to those of least weasels from the western Palearctic, with a focus on the Mediterranean region. Our results provide no evidence to support the view that the Egyptian weasel is genetically distinct from the least weasel, as we found that, for both Cytochrome b and control region, haplotypes were shared between the two taxa. Specifically, the Cytochrome b and control region haplotypes detected in the Egyptian weasel were also present in M. nivalis from Turkey and Malta, two populations genetically analysed here for the first time. Our results suggest that the Egyptian weasel is distinct from the least weasel populations currently living in the Maghreb, which were inferred to be the result of an earlier colonization of North Africa, but the genetic data alone do not allow us to determine whether the Egyptian weasel is native or introduced. Nevertheless, the observed genetic patterns, together with the weasel fossil record in Israel and the unique commensal lifestyle of the Egyptian weasel, are consistent with the hypothesis that the Egyptian population is a relict of past range expansion from the Levant into Egypt. We suggest that the large size and characteristic sexual dimorphism of the Egyptian weasel are likely to represent ecotypic variation, but genomic studies are required to clarify the extent of its functional genetic divergence.
Assuntos
DNA Mitocondrial/genética , Genética Populacional , Mustelidae/genética , Filogenia , Animais , Teorema de Bayes , Citocromos b/genética , Egito , Haplótipos , Região do Mediterrâneo , Análise de Sequência de DNARESUMO
Daily activity rhythms are nearly universal among animals and their specific pattern is an adaptation of each species to its ecological niche. Owing to the extremely consistent nocturnal patterns of activity shown by golden hamsters (Mesocricetus auratus) in the laboratory, this species is a prime model for studying the mechanisms controlling circadian rhythms. In contrast to laboratory data, we discovered that female hamsters in the wild were almost exclusively diurnal. These results raise many questions about the ecological variables that shape the activity patterns in golden hamsters and the differences between laboratory and field results.
