RESUMO
Untreated sewage samples from 12 cities in the United States were screened for the presence of recently characterized RNA and DNA viruses found at high prevalence in the stool specimens of South Asian children. Genetic variants of human cosaviruses and cardioviruses in the Picornaviridae family and of DNA circoviruses and human bocaviruses were detected, expanding the known genetic diversity and geographic range of these newly identified viruses. All four virus groups were detected in sewage samples of less than a milliliter from multiple U.S. cities. PCR screening of particle-protected viral nucleic acid in sewage samples could therefore rapidly establish the presence and determine the diversity of four newly described enteric viruses in large urban populations. More frequent and deeper sampling of viral nucleic acids in sewage samples could be used to monitor changes in the prevalence and genetic composition of these and other novel enteric viruses.
Assuntos
Bocavirus/classificação , Cardiovirus/classificação , Circovirus/classificação , Variação Genética , Picornaviridae/classificação , Esgotos/virologia , Bocavirus/genética , Bocavirus/isolamento & purificação , Cardiovirus/genética , Cardiovirus/isolamento & purificação , Circovirus/genética , Circovirus/isolamento & purificação , Análise por Conglomerados , DNA Viral/genética , Humanos , Dados de Sequência Molecular , Filogenia , Picornaviridae/genética , Picornaviridae/isolamento & purificação , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência , Estados UnidosRESUMO
Molecular analysis of two Australo-Papuan rainforest birds exhibiting correlated 'leapfrog' patterns were used to elucidate the evolutionary origin of this unusual pattern of geographical differentiation. In both sooty owls (Tyto) and logrunners (Orthonyx), phenotypically similar populations occupy widely disjunct areas (central-eastern Australia and upland New Guinea) with a third, highly distinctive population, occurring between them in northeastern Queensland. Two mechanisms have been proposed to explain the origin of leapfrog patterns in avian distributions: recent shared ancestry of terminal populations and unequal rates or phenotypic change among populations. As the former should generate correlated patterns of phenotypic and genetic differentiation, we tested for a sister relationship between populations from New Guinea and central-eastern Australia using nuclear and mitochondrial DNA sequences. The resulting phylogenies not only refute recent ancestry as an explanation for the leapfrog pattern, but provide evidence of vastly different spatio-temporal histories for sooty owls and logrunners within the Australo-Papuan rainforests. This incongruence indicates that the evolutionary processes responsible for generating leapfrog patterns in these co-distributed taxa are complex, possibly involving a combination of selection and drift in sooty owls and convergence or retention of ancestral characteristics in logrunners.
Assuntos
DNA Mitocondrial/genética , Ecossistema , Aves Canoras/genética , Estrigiformes/genética , Adenosina Trifosfatases/genética , Animais , Austrália , Sequência de Bases , Evolução Biológica , Grupo dos Citocromos b/genética , DNA Mitocondrial/química , Demografia , Geografia , Dados de Sequência Molecular , Papua Nova Guiné , Filogenia , Dinâmica Populacional , Análise de Sequência , Aves Canoras/classificação , Estrigiformes/classificaçãoRESUMO
The bird fauna of Madagascar includes a high proportion of endemic species, particularly among passerine birds (Aves: Passeriformes). The endemic genera of Malagasy songbirds are not allied obviously with any African or Asiatic taxa, and their affinities have been debated since the birds first were described. We used mitochondrial sequence data to estimate the relationships of 13 species of endemic Malagasy songbirds, 17 additional songbird species, and one species of suboscine passerine. In our optimal trees, nine of the 13 Malagasy species form a clade. although these birds currently are classified in three different families. In all optimal trees, the sister to this endemic clade is a group of Old World warblers including both African and Malagasy birds. The endemic Malagasy songbird clade rivals other island radiations, including the vangas of Madagascar and the finches of the Galapagos, in ecological diversity.
Assuntos
DNA Mitocondrial/genética , Aves Canoras/genética , Animais , Sequência de Bases , DNA Mitocondrial/efeitos da radiação , Variação Genética , Funções Verossimilhança , Aves Canoras/classificação , Especificidade da EspécieRESUMO
This study is a phylogenetic analysis of the avian family Ciconiidae, the storks, based on two molecular data sets: 1065 base pairs of sequence from the mitochondrial cytochrome b gene and a complete matrix of single-copy nuclear DNA-DNA hybridization distances. Sixteen of the nineteen stork species were included in the cytochrome b data matrix, and fifteen in the DNA-DNA hybridization matrix. Both matrices included outgroups from the families Cathartidae (New World vultures) and Threskiornithidae (ibises, spoonbills). Optimal trees based on the two data sets were congruent in those nodes with strong bootstrap support. In the best-fit tree based on DNA-DNA hybridization distances, nodes defining relationships among very recently diverged species had low bootstrap support, while nodes defining more distant relationships had strong bootstrap support. In the optimal trees based on the sequence data, nodes defining relationships among recently diverged species had strong bootstrap support, while nodes defining basal relationships in the family had weak support and were incongruent among analyses. A combinable-component consensus of the best-fit DNA-DNA hybridization tree and a consensus tree based on different analyses of the cytochrome b sequences provide the best estimate of relationships among stork species based on the two data sets.
