Rafael Bueno Noleto

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Characidium fishes with a sex chromosome system form a monophyletic group. This work presents data of Characidium lanei from the South Atlantic basin (Brazil), including an unknown type of ZW sex chromosome system for the groups including the presence of rDNA sites on sex chromosomes.
Constitutive heterochromatin represents a substantial portion of the eukaryote genome, and it is mainly composed of tandemly repeated DNA sequences, such as satellite DNAs, which are also enriched by other dispersed repeated elements, including transposons. Studies on the organization, structure, composition and in situ localization of satellite DNAs have(More)
Cytogenetic analysis in two sympatric species of pufferfish from Paraná Coast, Brazil, Sphoeroides spengleri (Tetraodontidae) and Chilomycterus spinosus (Diodontidae) revealed the presence of 2n = 46 and 2n = 50 chromosomes, respectively. In S. spengleri, the double FISH technique with 5S and 18S rDNA probes showed no syntenical organization, with both(More)
Chromosomal features, location and variation of the major and minor rDNA genes cluster were studied in three pufferfish species: Sphoeroides greeleyi and Sphoeroides testudineus (Tetraodontidae) and Cyclichthys spinosus (Diodontidae). The location of the major rDNA was revealed with an 18S probe in two loci for all species. The minor rDNA loci (5S rDNA) was(More)
Chromosomal rearrangements such as inversions can facilitate speciation even in the presence of gene flow. The present study aims to analyze the karyotypic variation in six populations of Geophagus brasiliensis from southern Brazil. All specimens showed 2n=48 chromosomes, but three karyotypes were found to have one, two or three pairs of submetacentric(More)
Smooth pufferfish of the family Tetraodontidae had become pure genomic models because of the remarkable compaction of their genome. This trait seems to be the result of DNA loss following its divergence from the sister family Diodontidae, which possess larger genomes. In this study, flow cytometry was used for estimate the genome size of four pufferfish(More)
We conducted a cytogenetic study of four hyline frog species (Dendropsophus elegans, D. microps, D. minutus and D. werneri) from southern Brazil. All species had 2n = 30 chromosomes, with interspecific and intraspecific variation in the numbers of metacentric, submetacentric, subtelocentric and telocentric chromosomes. C-banding and fluorochrome staining(More)
Two populations of Hollandichthys multifasciatus from headwaters of adjacent river coastal basins in Paraná state, southern Brazil, were cytogenetically studied in order to evaluate intraspecific divergences. Both populations presented 2n = 50 chromosomes, divided into 14m + 18sm + 18st in the sample from Antonina and 14m + 20sm + 16st for the population(More)
The Iguaçu River basin is a tributary to the upper Paraná River in southern Brazil, and is considered an important aquatic ecoregion that, although having few species of fish, 51-71% of these are apparently endemic. Ancistrus abilhoai is one of three recently described species for this basin and is currently considered endemic to the basin. In this study,(More)
The family Ariidae comprises approximately 130 catfish species on both warm-temperate and tropical continental shelves around the world. The systematics of the group is problematic, with several misidentification problems. In order to better understand the evolutionary relationships in the family, the present study used a cytogenetic approach to(More)