Mechanisms of chromosomal evolution in three European species of the Sorex araneus-arcticus group (Insectivora: Soricidae)

Presented are the R-banding patterns of the karyotypes of three European species of the Sorex araneus-arcticus group (Insectivora: Soricidae). The eight species of this Holarctic complex are characterized by sharing a male chromosomal set of XY1Y2 elements. Robertsonian and tandem translocations are common in this complex, at the population level as well as at the species level. The rough morphology of the karyotypes looks similar between all the species presently described. An R-banding technique RHG, RBG) has allowed us to make a comparative analysis of the chromosomal similarities in three species, namely S. araneus, S. coronatus and S. granarius. The data provide evidence that Robertsonian and tandem translocations, accompaniei in some cases by centromeric shifts, are the main, if not the only, mechanisms of chromosomal evolution in this grou. It appears that S. granarius presents a karotype which is most similar to the hypotheticar ancestral type from which the chromosomar sets of two other European species might be derived.