Filogeografia e citogenética do gênero Kerodon (CUIVER, 1825) (RODENTIA: CAVIIDAE)

• Autor(a) principal: Zappes, Ighor Antunes
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2288
• topic: Mocó; Citogenética; Filogeografia; Mocó; Cytogenetics; Phylogeography; CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA::BIOLOGIA MOLECULAR

Among mammals from Brazilian biomes, rodent of genus Kerodon (Wied 1820), or mocó, englobes one of the most specialist species and one of the few endemic mammals from Brazilian semiarid, or caatinga, Kerodon rupestris, and other species from semi-arid islands within the savannah, or cerrado, Kerodon acrobata. Their distribution is fragmented, due to discontinuous rock outcrops where these animals live. It suggests an intraspecific variation among their populations. Cranial and cytogenetic studies with K. rupestris had showed a separation in three groups: one in Minas Gerais state, other in Bahia and the last in Ceará. This study investigated genes from populations of Kerodon species, in order to make analysis to check inter and intra variation. A small group from another locality, probably a hybrid, was also analyzed. We first characterize the karyotype of a female from K. acrobata. Giemsa staining, nucleolar organizer region (NOR) banding, C-positive heterochromatin banding and DAPI fluorescence were used in N metaphases of a specimen collected in Asa Branca Farm, in Aurora do Tocantins municipality, Tocantins state, Brazil. K. acrobata showed the same diploid number, fundamental number and chromosome morphology as Kerodon rupestris. But its NOR location and heterochromatin distribution patterns indicated a unique cytogenetic profile when compared to its sister species, emphasizing the evolutionary uniqueness of this relatively new and unknown species. This record also extends the distribution of this species northward. We also extracted DNA from livers and amplifications were made for gene Adh1-I2. After sequencing, alignments were done with ClustalW software. Phylogeny was inferred using Maximum Parsimony and Maximum Likelihood methods using PAUP software. Bayesian Analysis was also made, using MrBayes software. One haplotype network was done with DnaSP and Network. All trees and network showed similar results. These relations agree with variation observed in previous studies, separating K. rupestris populations in several groups. K. acrobata was also split in other groups, and some results indicate that the hybrid population is in fact a K. rupestris group in speciation. A possible explanation for these partitions is the fact that rock outcrops fragmented geography from caatinga during Pleistocene and events of expansion/retraction of the habitat may have generated population isolation and differentiation.