Enzyme polymorphism in Malayan rats of the Subgenus Rattus

Electrophoretic variation in nine red cell proteins was analysed in 256 specimens belonging to six species of Malayan Rattus (including one with two subspecies) of the subgenus Rattus. The average proportion of loci heterozygous per individual for the taxa analysed is 0.04. With the exception of Rattus rattus diardii, R. tiomanicus tiomanicus and R. t. jalorensis, individuals of the other species could be identified by specific electrophoretic phenotypes of one or more of the markers analysed. Relationships among the species studied were elucidated by the classical and phenetic approaches employing electrophoretic characters. The results obtained by the two approaches were similar in most respects and they corresponded better with results based on morphological characters than those based on cytological characters.