Chromosomal Comparisons Among And Within Populations Of Simulium (chirostilbia) Pertinax (diptera, Simuliidae).

Chromosomal studies were carried on six larval populations of Simulium (Chirostilbia) pertinax from different locations in Brazil. Larvae were collected in the states of Paraná, Rio Grande do Sul, Rio de Janeiro and São Paulo. Polytene chromosome map comparisons within and among populations showed no differences in banding pattern, except for some limited polymorphism (secondary NOR and four band polymorphisms). There were no chromosomal variations associated with the resistance or susceptibility of the larvae to temephos. The chromosomal homosequentiality found among the six populations suggests that S. pertinax may be a monomorphic species.96365-

Sexual Dimorphism In Ramphastos Toco And Ramphastos Dicolorus (piciformes, Aves).

Phenotypic sexual dimorphism seems to be rare in the Ramphastidae family, except in Pteroglossus viridis and in the genus Selenidera. Many breeders of wild birds believe that specimens of Ramphastos toco can be sexed using bill characteristics. In this study, various discriminant phenotypic variables were analyzed in birds which were sexed cytogenetically. Fifty-one specimens of R. toco and 20 R. dicolorus were studied. The statistically significant parameters which served to distinguish the sex in these species were the length of the culmen and tomium, length of the lower corneous beak and the cloaca. Using these parameters, captive bird breeders can determine sex of R. toco specimens by phenotypic analysis and form breeding couples more quickly.51241-

Unraveling the variability and genetic structure of barker frog Physalaemus Cuvieri(Leiuperinae) populations from different regions of Brazil

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORThe barker frog Physalaemus cuvieri is widely distributed in South America and is found in all regions of Brazil. Significant intraspecific morphological variation in this species has been reported. To determine the genetic structure of the natural Brazilian populations of P. cuvieri, 10 different populations geographically separated by 99.41 to 2936.75 km were evaluated using 10 polymorphic microsatellite loci. In addition, mitochondrial DNA data were analyzed to determine genetic distance between the populations. The genetic variation was found to be significant in most of the populations (HE ranged from 0.40 to 0.59, and allelic richness ranged from 2.07 to 3.54). An FST value of 0.27 indicated that high genetic structure was present among the P. cuvieri populations. STRUCTURE analyses grouped the 10 populations into nine clusters and indicated that only two of the populations were not genetically differentiated. The genetic distance calculated from the mitochondrial DNA data showed values <0.03 for seven of the populations.The barker frog Physalaemus cuvieriis widely distributed in South America and is found in all regions of Brazil. Significant intraspecific morphological variation in this species has been reported. To determine the genetic structure of the natural Brazili13380558065FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR06/59697-7sem informaçã

Study Of Closely Related Species Within The Physalaemus Cuvieri Group (anura): Contribution Of Microsatellite Markers.

Various species of the Physalaemus cuvieri group of frogs are difficult to distinguish morphologically, making molecular analysis an attractive alternative for indentifying members of this group, which is considered to be at risk because of loss of habitat. The genetic structure of natural populations of P. ephippifer and P. albonotatus species was investigated and analyzed, together with that of five previously studied populations of P. cuvieri. Nine microsatellite loci were used in the analyses. The overall G(ST) value (0.46) revealed high genetic variation among the populations, as expected for different species. Bayesian analysis implemented by the STRUCTURE software clustered the seven populations into seven groups (K = 7). All the P. albonotatus and P. ephippifer specimens were grouped into a single cluster, both species showing clear differentiation from P. cuvieri. The different grouping based on these microsatellites of some P. cuvieri individuals from Porto Nacional and from Passo Fundo suggests that they could be a new species, indicating a necessity for taxonomic reevaluation. Despite the intrinsic difficulties in analyzing closely related species, the nine microsatellite loci were found to be adequate for distinguishing these three species of the P. cuvieri group and their populations.101434-4

The karyotype of three Brazilian Terrarana frogs (Amphibia, Anura) with evidence of a new Barycholos species

A recent substantial rearrangement of the 882 described eleutherodactyline frog species has considerably improved the understanding of their systematics. Nevertheless, many taxonomic aspects of the South American eleutherodactyline species remain unknown and require further investigation using morphological, cytogenetic and molecular approaches. In this work, the karyotypes of the Brazilian species Ischnocnema juipoca (Atibaia and Campos do Jordão, SP), Barycholos cf. ternetzi (Uberlândia, MG, and Porto Nacional, TO), and Pristimantis crepitans (Chapada dos Guimarães and São Vicente, MT) were analyzed using Giemsa staining, Ag-NOR labeling, and C-banding techniques. All individuals had a diploid number of 22 chromosomes, but the Fundamental Numbers were different among species. The herein described low chromosome number of Pristimantis crepitans is unique within this genus, suggesting that cytogenetically this species is not closely related either to its congeneric species or to Ischnocnema. In addition, karyotype differences, mainly in the NOR position, clearly distinguished the two Barycholos populations, besides indicating the existence of a so far undescribed species in this genus. A taxonomic review could clarify the systematic position of P. crepitans and verify the hypothetic new Barycholos species

Conserved karyotypes in the Hyla pukhella species group (Anura, Hylidae)

Cytogenetic analyses were done on specimens of Hyla marginata and on three populations of H. semiguttata differing in morphology and in the physical parameters of their advertisement call, as well as in individuals of Hyla sp. (aff. semiguttata). All specimens had 2n = 24 chromosomes with a morphology very similar to that of other 24-chromosome Hyla species. Hyla semiguttata and H. marginata showed the same C-banding pattern but were distinguished by the location of the NOR on pair 1 in H. semiguttata (in the three populations) and Hyla sp. (aff. semiguttata), and on pair 10 in H. marginata. The H. semiguttata populations did not differ cytogenetically, despite variations in their morphology and advertisement calls. Similarly, H. semiguttata and H. p. joaquini studied previously had identical C-banding patterns and NOR locations, suggesting that they are very closely related

Characterization of the heterochromatin of Drosophila nebulosa

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOMitotic and polytene chromosomes of Drosophila nebulosa were subjected to C- and G-banding methods and to culture in a medium containing Hoechst 33258 in order to compare two types of centromeric heterochrornatln of chromosomes 2 ({3-heterochromatin) and X (a-heterochromatin). These types of heterochromatin did not differ in response to the various methods.The heterochromatin of the Y chromosome differed from that of the other chromosomes, reflecting peculiarities in its composition. The chromosomes of D. nebulosa were simpler and more homogeneous than those of other Drosophila species. The results agree with the phylogenetic position of D. nebulosa when compared with more complex chromosome patterns observed in phylogenetically higher Drosophila species which are more evolved in character.48193111124CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOsem informaçã