Cytogenetics of mole rats of the Spalax ehrenbergi superspecies from Jordan (Spalacidae, Rodentia)

Karyotypes (chromosome sets and the banding patterns (G-, C- and Ag-NOR) of the Spalax ehrenbergi superspecies across 12 localities from Jordan are described for the first time. All mole rats from this region (excluding two individuals from Madaba with 2n = 62) have a diploid chromosome number of 2n = 60 but they display geographical variability in the number of autosoma] arms (NFa = 68, 70, 72 and 74). The most widely distributed cytotype (from Madaba in the north to Wadi Musa, near Petra, in the south) has four pairs of small biarmed chromosomes. Karyotypes of two northern populations (Irbid and Zarqa) contain six pairs of small biarmed chromosomes. The intermediate karyotype with five small biarmed chromosomes is found 25 km north of Madaba, and a polymorphic population (Mt. Nebo) with five (2 animals) and four (4 animals) pairs of small biarmed chromosomes occurs between the northern and southern cytotypes. Geographical variability is also displayed by the short arm length in the first subtelocentric autosomes. All karyotypes have a similar C-banding pattern, with the exception of heterochromatin distribution in the variable first pair. Comparative analysis of G-banded chromosomes indicated that NF differentiation is due to pericentric inversions or centromere shift. Relationships between Jordanian, Israeli, and Turkish species of the Spalax ehrenbergi superspecies are discussed.