Torres RA, Motta TS, Nardino D, Adam ML, Ribeiro J. 2009. Chromosomes, RAPDs and evolutionary trends of the Neotropical fish Mimagoniates microlepis (Teleostei: Characidae: Glandulocaudinae) from coastal and continental regions of the Atlantic forest, Southern Brazil. Acta Zoologica 89(3): 253-259. [連結]ABSTRACT
Chromosome and random amplified polymorphic DNA (RAPD) markers of samples of Mimagoniates microlepis were studied to test the hypothesis that a vicariant event occurred as the result of the orogeny of the coastal mountain range (Serra do Mar; southeastern and southern Brazil). Conventional karyotypes and nucleolar organizer region (Ag-NOR) phenotypes of two samples of M. microlepis from the headwaters of the Iguaçu River (southern Brazil) were compared both with each other and with other local populations of the species in the coastal drainage of southeastern Brazil. Additional molecular data (RAPD markers and genetic diversity) were obtained from specimens from coastal and continental regions of southern Brazil. The same diploid number (52 chromosomes), karyotypic formula and Ag-NOR phenotype were found for both analysed samples from the Iguaçu River. A genetic discontinuity was discovered in the comparison of the karyotypical formula of the Iguaçu samples with those from coastal drainages of the region. Polymerase chain reaction-RAPD markers revealed strikingly different molecular profiles between coastal and continental samples and indications of a high degree of genetic variation. Based on these results, we provide some comments on the biogeographical patterns and evolutionary trends for M. microlepis from coastal and continental regions of southeastern/southern Brazil.
