Molecular characterization and mitochondrial sequence variation in two sympatric species of Proechimys (Rodentia : Echimyidae) in French Guiana

Variations in mitochondrial DNA characters were used to characterize two mo rphologically similar and sympatric species of Neotropical terrestrial rode nts of the genus Proechimys (Mammalia: Echimyidae). We sequenced both cytoc hrome b (1140 pb) and part of the control region (445 pb) from four individ uals of P. cuvieri and five of P. cayennensis from French Guiana, which all owed us to depict intra- and inter-specific patterns of variation. The phyl ogenetic relationships between the nine sequences evidence the monophyly of each species, and illustrate that more polymorphism might exist within P. cuvieri than within P. cayennensis. By developing species-specific primers to amplify a fragment of the cytochrome b gene, we were able to identify 50 individuals of Proechimys spp. caught in two localities of French Guiana. In both sites of primary rainforests, we showed that the two species live i n syntopy, and this observation emphasizes the need to document ecological differences which should exist in order to diminish inter-specific competit ion. (C) 2000 Elsevier Science Ltd. All rights reserved.