Morphological descriptions, taxonomic history and distribution data of Omophoita species recorded for southern Brazil (states of Paran, Santa Catarina and Rio Grande do Sul) are presented. Through the analysis of the existing literature, databases, loaned material, and specimen collecting, we studied seven species of Omophoita recorded for southern Brazil: O. communis (Bechyn 1959), O.
View Article and Find Full Text PDFDrosophila buzzatii (Diptera: Drosophilidae) is a fly that breeds exclusively on decaying tissues of cacti species widely distributed in tropical and subtropical areas of South America. This distribution includes biomes in distinct climatic regimes (e.g.
View Article and Find Full Text PDFCichlids constitute a diverse monophyletic group that have developed adaptive strategies to thrive in diverse environments. represents an example of diversification on the South American Andean uplift, providing a key model for understanding the evolution of biogeographic patterns. In this study, we analyzed the species using two mitochondrial markers (, ) and one nuclear marker () in a populational level.
View Article and Find Full Text PDFGenes (Basel)
November 2019
The species complex is one of the most studied with respect to origin, distribution, and frequency of B chromosomes, and is considered a model organism for evolutionary studies. Research using population inferences about the occurrence and frequency of the B chromosome shows seasonal variation between sexes, which is associated with the presence of this supernumerary element. We hypothesized that the B chromosome could influence the sex ratio of these animals.
View Article and Find Full Text PDFAstyanax is an abundant fish genus in South America. Some species of this group are characterized by the presence of B chromosomes and absence of morphologically differentiated sex chromosomes. In this study, we used quantitative real-time polymerase chain reaction to characterize mRNA expression of dmrt1 in Astyanax scabripinnis gonads.
View Article and Find Full Text PDFIn addition to its wide geographical distribution, osteoglossiform fishes represent one of the most ancient freshwater teleost lineages; making it an important group for systematic and evolutionary studies. These fishes had a Gondwanan origin and their past distribution may have contributed to the diversity present in this group. However, cytogenetic and genomic data are still scarce, making it difficult to track evolutionary trajectories within this order.
View Article and Find Full Text PDFMost part of the eukaryotic genome is composed of repeated sequences or multiple copies of DNA, which were considered as "junk DNA", and may be associated to the heterochromatin. In this study, three populations of Astyanax aff. scabripinnis from Brazilian rivers of Guaratinguetá and Pindamonhangaba (São Paulo) and a population from Maringá (Paraná) were analyzed concerning the localization of the nucleolar organizer regions (Ag-NORs), the As51 satellite DNA, the 18S ribosomal DNA (rDNA), and the 5S rDNA.
View Article and Find Full Text PDFFive breeding colonies of the Roseate spoonbill (Aves: Platalea ajaja) from two Brazilian wetland areas (Pantanal and Taim marshes) were sampled, and domain I of the mitochondrial DNA control region (483 bp) was sequenced in 50 birds. The average haplotype diversity (h = 0.75, s = 0.
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