ROBERTSONIAN CHROMOSOMAL VARIATION IN THE HOUSE MUSK SHREW (SUNCUS-MURINUS, INSECTIVORA, SORICIDAE) AND THE COLONIZATION HISTORY OF THE SPECIES

A high-resolution G-banding technique was used to identify five metace ntrics that characterize Suncus murinus from Sri Lanka. These metacent rics were shown to be the product of Robertsonian fusion of acrocentri c chromosomes identical to those in the standard karyotype defined by M.B. Rogatcheva et al. Two of the metacentrics in the Sri Lankan shrew s (Rb(10.12) and Rb(14.15)) were the same as those reported by C.H. Sa m et al, in Malayan populations of S. murinus. This finding provides s trong support for the suggestion of T.H. Yosida that metacentric-carry ing shrews colonized Malaya from Sri Lanka and hybridized with individ uals of standard karyotype, generating the Robertsonian polymorphism n ow observed. In addition to the Robertsonian variation in S. murinus, we have used our high resolution technique (G- and C-banding) to chara cterize variants on chromosome 7, the X chromosome, and the Y chromoso me.