Margaret Maria de Oliveira Corrêa

Cytogenetic studies on the Perciformes Orthopristis ruber(Haemulidae) and Scartella cristata (Blenniidae)

SUMMARYTwo Perciformes species (Orthopristis ruber and Scartella cristata) occurring along the southeastern coast of Brazil (Guanabara Bay, RJ) were analyzed cytogenetically by standard techniques, by silver nitrate staining and by C-banding. The results obtained in the present study confirm the karyotypic stability observed among Perciformes since both species present a diploid complement consisting of 48 chromosomes. The two species presented similar C-banding patterns revealing constitutive heterochromatin blocks in centromeric and telomeric positions in most chromosomes in the complement. S. cristata showed the presence of a NOR pair located subterminally in one of the largest subtelocentric pairs. The results obtained for O. ruber about this feature were not satisfactory.

A new karyotype of Wiedomys pyrrhorhinus (Rodentia: Sigmodontinae) from Chapada Diamantina, northeastern Brazil

A new karyotype of Wiedomys pyrrhorhinus (Wied, 1821) is described, including G- and C-banding and Ag-NOR sites from specimens collected in the municipality of Morro do Chapeu, situated in the northern region of the Chapada Diamantina, state of Bahia. Karyological studies of W. pyrrhorhinus have shown a constant diploid number (2n) of 62 with two different numbers of autosomal arms (FNa): 86 and 90, respectively. The new karyotype revealed 2n = 62 and FNa = 104, being the higher autosomal number found so far for this genus. The X chromosome is a large acrocentric and the Y chromosome is a small acrocentric. The analysis of the karyotype morphology suggests that this new karyotype is more closely related to the previous karyotype with 2n = 62 and FNa = 90, described from Caetite, Bahia State. Further studies, comparing different populations of W. pyrrhorhinus, including molecular approaches, may help to better understand the geographical limits of each population and their phylogenetic relationships in the Caatinga biome

Karyotypic and phylogeographic analyses of Cormura brevirostris (Chiroptera, Emballonuridae)

Cormura brevirostris is a rare and poorly known species of emballonurid bat that occurs in Central America and South America across the Amazonian region. Previous work showed that karyotypes of C. brevirostris from Colombia, Suriname, and the Brazilian Amazon presented 2n = 22 and FN = 40, although small differences in chromosome composition have been observed among these karyotypes. Phylogenetic studies using nuclear and mitochondrial markers also showed differences between Central and South American C. brevirostris individuals. We describe the karyotype of an adult male C. brevirostris from the Brazilian Amazon and compare it to other karyotypes reported for this species. We also investigate phylogenetic relationships within this species using 2 mitochondrial and 1 nuclear gene. Morphological characters and measurements of the Brazilian specimen matched those described for C. brevirostris. The karyotype displayed a C-banding pattern similar to those described for C. brevirostris from other localities. Phylogenetic analyses confirmed the monophyly of Cormura, but each marker showed a different relationship. Karyological data showing more than 1 lineage and deep intraspecific mitochondrial lineages suggest that this taxon could be a species complex, requiring additional taxonomic studies to elucidate species limits and phylogenetic relationships within the genus Cormura. Cormura brevirostris é uma espécie rara e pouco conhecida de morcegos embalonurídeos que ocorre na América Central e em toda a região Amazónica da América do Sul. Trabalhos anteriores mostraram que os cariótipos de C. brevirostris da Colômbia, do Suriname e da Amazônia brasileira apresentaram 2n = 22 e FN = 40, embora pequenas diferenças na composição dos cromossomos tenham sido observadas entre esses cariótipos. Estudos filogenéticos utilizando marcadores nucleares e mitocondriais também mostraram diferenças entre os indivíduos de C. brevirostris das Américas Central e do Sul. Descrevemos o cariótipo de um adulto de C. brevirostris da Amazônia brasileira e comparamos com outros cariótipos relatados para essa espécie. Também investigamos as relações filogenéticas dentro desta espécie usando 2 genes mitocondriais e 1 nuclear. Medidas e caracteres morfológicos do espécime brasileiro coincidiram com as descritas para C. brevirostris. O cariótipo mostrou um padrão de bandas-C semelhante àqueles descritos para C. brevirostris de outras localidades. As análises filogenéticas confirmaram a monofilia de Cormura, mas cada marcador mostrou um relacionamento diferente. Os dados cariológicos que mostram mais de 1 linhagem e linhagens mitocondriais de profunda divergência intraspecífica sugerem que este táxon pode ser um complexo de espécies, necessitando de estudos taxonômicos adicionais para elucidar os limites das espécies e as relações filogenéticas dentro do gênero Cormura.