Flora Maria de Campos Fernandes

Diversification of Ramphastinae (Aves, Ramphastidae) prior to the Cretaceous/Tertiary boundary as shown by molecular clock of mtDNA sequences

Partial cytochrome b and 12S rDNA mitochondrial DNA sequences of eight representatives of the Ramphastidae family were analyzed. We applied the linearized tree method to identify sequences evolving at similar rates and estimated the divergence times among some of the taxa analyzed. After excluding Ramphastos tucanus and Capito dayi from our data set, the remaining taxa presented a constant rate of DNA substitution, and branch lengths could be re-estimated with a clock constraint using the maximum likelihood method. Branch lengths were calibrated assuming that Galliformes and Piciformes split around 100 million years ago (mya). Our results indicate that Ramphastinae, and probably Capitoninae, diverged from other Piciformes in the Late Cretaceous (~82 mya), suggesting that Piciformes is another avian order that survived the mass extinction event occurred 65 mya at the Cretaceous/Tertiary (K/T) boundary. The divergence times estimated within the Ramphastinae genera cover the period from the Middle Eocene (around 47 mya) through the Late Miocene (9.5 mya). Our estimate of divergence time is coincidental with the split of the African and the South American continents and other intense geologic activities and modifications of the areas which correspond to the current Neotropics. These events might have influenced the diversification of Ramphastinae in South America.

Molecular subtyping of Campylobacter jejuni subsp. jejuni strains isolated from different animal species in the state of São Paulo, Brazil

O objetivo do presente trabalho foi caracterizar geneticamente estirpes de Campylobacter jejuni subsp. jejuni isoladas de humanos e de diferentes origens animais (bovinas, suinas, caes, primatas, javalis, suinos e aves de corte). Um total de 828 amostras (fezes, carcacas, fetos abortados e utero histerectomizado) foram analisadas por metodos de rotina bacteriologica e 36 estirpes de C. jejuni foram isoladas. Trinta estirpes de origem fecal humana foram obtidas de laboratorios de analises clinicas da cidade de Sao Paulo. As 66 estirpes de C. jejuni isoladas foram submetidas a caracterizacao genetica. Oligonucleotideos baseados no gene fla A foram usados na reacao de polimerase em cadeia (PCR) e amplificou um fragmento de 702 pb. Os produtos obtidos pela PCR foram avaliados pelas tecnicas de sequenciamento e analise genealogica. Analise da variabilidade genetica das 66 estirpes revelou 44 diferentes subtipos de C. jejuni. Um subtipo de origem humana apresentou sequencia identica a de C. jejuni depositada no GenBank (GENBANK acesso numero AF050186). A subtipagem das estirpes de C. jejuni baseadas no sequenciamento da regiao variavel do gene fla A e na analise do alinhamento das sequencias pelo metodo da Maxima Parcimonia, mostraram-se altamente discriminatorios fornecendo melhores condicoes para a correta diferenciacao entre estirpes originarias de surto e as isoladas esporadicamente. Este foi o primeiro estudo de subtipagem molecular de estirpes de C. jejuni de origem humana e animal utilizando a tecnica do sequenciamento com analise genealogica realizado no Estado de Sao Paulo, Brasil.

Cytogenetic characterization of the strongly electric Amazonian eel, Electrophorus electricus (Teleostei, Gymnotiformes), from the Brazilian rivers Amazon and Araguaia

A karyotype analysis of the electric eel, Electrophorus electricus (Teleostei, Gymnotiformes), a strongly electric fish from northern South America, is presented. Two female specimens were analyzed, one from the Amazon River and one from the Araguaia River. The specimens had a chromosomal number of 2n = 52 (42M-SM + 10A). C-bands were present in a centromeric and pericentromeric position on part of the chromosomes; some interstitial C-bands were also present. Heteromorphic nucleolus organizer regions (NORs) were detected in two chromosome pairs of the specimen from the Amazon River. The chromosome number and karyotype characteristics are similar to those of other Gymnotidae species. The genera Electrophorus and Gymnotus are positioned as the basal lineages in the Gymnotiformes phylogeny.

A new Badnavirus species detected in Bougainvillea in Brazil

Badnavirus in Bougainvillea spectabilis showing virus-like symptoms was identified by the presence of bacilliform particles, measuring 125–130 × 30–40 nm in leaf-dip preparations and by analysis of its putative open reading frame 3 sequence. The virus, tentatively named Bougainvillea bacilliform virus (BBV), had the highest identities (up to 60%) with Spiraea yellow leaf spot virus, Gooseberry vein banding associated virus, Taro bacilliform virus, and Citrus yellow mosaic virus. In phylogenetic analysis, BBV clustered with Badnavirus putative species. Attempts to transmit the virus to several hosts failed. This is the first report of a new Badnavirus detected in Bougainvillea.

Molecular markers in Chinese carps and their interspecific hybrids

A sample consisting of 2 Ctenopharyngodon idella (grass carp) females, 2 Aristichthys nobilis (bighead carp) males, and 10 interspecific hybrids was analyzed using a multidisciplinary approach. The 10 hybrids were the only surviving specimens of a crossbreeding experiment. The cytological approach, involving the measurement of the largest axis of the erythrocytes, revealed that the parental species were diploid, whereas, among the hybrids, eight individuals were triploid, and two were diploid. Two of the triploid individuals were analyzed cytogenetically and showed 2n = 3X = 72 chromosomes. Using the biochemical and molecular approaches, it was possible to confirm that one of the C. idella specimens was the true mother of the hybrids. Those data also allowed to rule out both males from parenthood. The molecular analyses also indicated the absence of gynogenetic individuals among the hybrids. We discuss the use of a multidisciplinary approach as an efficient tool in the monitoring of aquaculture programs.