ABSTRACT
The migratory catfish Brachyplatystoma vaillantii is one of the most important fishery resources in the Amazon. Intense capture occurs associated to its life cycle. In order to know the genetic status, we sequenced the mitochondrial DNA control region from 150 individuals of B. vaillantii, collected in five fishing landing locations, covering the length of the Solimões-Amazonas River in Brazil. Genetic diversity parameters suggest there is no genetic differentiation between the five localities. Population's expansion indicated by R 2 and Fu's Fs tests was also confirmed by the high number of unique haplotypes found. The Analyses of molecular variance indicated that nearly all variability was contained within locations (99.86%), and estimates of gene flow among B. vaillantii were high (F ST = 0.0014). These results suggest that Brachyplatystoma vaillantii forms a panmitic population along the Solimões-Amazonas River and, has greater genetic variability than other species of the Brachyplatystoma genus available so far. Although the influence of different tributaries on B. vaillantii migration patterns remains uncertain, a single population in the main channel should be consider in future policies for management of this resource. However, since the species' life cycle uses habitats in several countries, its management and conservation depend greatly of internationally joined efforts.(AU)
O bagre migrador, Brachyplatystoma vaillantii, é um dos mais importantes recursos pesqueiros da Amazônia. Intensa captura ocorre associada ao seu ciclo de vida. Para conhecer seu status genético, sequenciamos a região de controle do DNA mitocondrial de 150 indivíduos, coletados em cinco locais de desembarque pesqueiro, abrangendo toda a extensão do rio Solimões-Amazonas no Brasil. Os parâmetros de diversidade genética sugerem que não existe diferenciação genética entre as cinco localidades amostradas. A expansão populacional indicada pelos testes R 2 e Fs de Fu, também foi confirmada pelo elevado número de haplótipos únicos encontrados. A análise de variância molecular indicou que quase toda a variabilidade estava contida nas localidades (99,86%), e as estimativas de fluxo gênico desta espécie eram altas (F ST = 0,0014). Esses resultados sugerem que Brachyplatystoma vaillantii forma uma população panmítica ao longo do rio Solimões-Amazonas com maior variabilidade genética que outras espécies do gênero Brachyplatystoma disponíveis no momento. Embora a influência dos diferentes afluentes na migração de B. vaillantii permaneça incerta, em futuras políticas de gestão deste recurso deve-se considerá-lo como uma única população no canal principal. Entretanto, uma vez que seu ciclo de vida abrange habitats em vários países, seu manejo e conservação dependem muito de esforços internacionais em conjunto.(AU)
Subject(s)
Animals , Genetic Variation , Catfishes , Ecosystem , Fisheries , Forecasting , GeneticsABSTRACT
Phylogenetic relationships among Neotropical deer genera (Artiodactyla: Cervidae) by means of DNAmt sequences and microsatellite markers. The current work shows two molecular phylogenetic analyses on Neotropical deers. In the first analysis, the mitochondrial control region (D-loop) was sequenced in six Odocoileinae species from Latin America, using the sequences of two Muntiacinae as outgroups. The results obtained were as follows: A sequence of Mazama americana showed a striking relationship with several sequences of Odocoileus in contrast to that expected, since this M. americana haplotype, from a Mexican origin, was not associated with several Bolivian Mazama sequences analyzed. This could put forward that this genera is not monophyletic. On the other hand, these Bolivian Mazama formed a clade with Pudu puda and Ozotoceros bezoarticus. Likely, an Odocoileus virginianus sequence from the Central area of Colombia showed a more strong relationship with a Northamerican O. heminonus sequence than with the other O. virginianus sequences of Colombian origin as well. This could be explained by means of various different hypotheses. The first is the existence of common ancestral haplotypes between both species. Another one is the reiterative hybridization among both Odocoileus species before the migration of O. virginianus from North America to South America. Moreover, the maximum parsimony analysis showed an intense relationship between the Muntiacinae and this Neotropical Cervidae clade. In addition, and adding credence to the relevant polyphyletism found in Mazama by means of the mitochondrial control region DNA sequences, a second analysis with 16 DNA microsatellite loci also showed a higher genetic relationship between M. americana and O. virginianus, than between the first species regard to Mazama gouazoubira. Rev. Biol. Trop. 55 (2): 723-741. Epub 2007 June, 29.
El presente trabajo muestra dos análisis moleculares sobre la filogenia de los cérvidos neotropicales. En uno se secuenció la región control del mtDNA (D-loop) de seis especies de Odocoileinae, utilizándose las secuencias de dos Muntiacinae como elementos externos. Se evidenciaron los siguientes resultados: La secuencia de una Mazama americana, de origen mexicano, presentó una fuerte relación filogenética con las diversas secuencias estudiadas de Odocoileus, contrario a lo esperado ya que, a priori, debería haberse asociado con las secuencias analizadas de otros ejemplares de Mazama de origen boliviano. Esto pone en evidencia que este género no es monofilético. A su vez, las secuencias de los ejemplares bolivianos de Mazama formaron una agrupación con secuencias de Pudu puda y O. bezoarticus. Una secuencia de O. virginianus, del área central de Colombia, presentó más relación con la secuencia de un O. hemionus norteamericano que con las restantes secuencias analizadas de O. virginianus, también de origen colombiano. Esto puede reflejar varias explicaciones hipotéticas, tales como la existencia de haplotipos ancestrales comunes entre ambas especies de Odocoileus, hasta la hibridación en Norteamérica entre ambos taxones antes de su penetración en Sudamérica. Los análisis de máxima parsimonia presentan una especial relación entre los Muntiacinae y el clado de los ciervos sudamericanos. El segundo análisis filogenético hizo uso de 16 marcadores nucleares microsatélites. Aunque, en principio, estos marcadores no son los más recomendables para estudios filogenéticos intergenéricos, los resultados muestran, al igual que el ADN mitocondrial, una mayor relación entre M. americana y O. virginianus que entre la primera especie y M. gouzaoubira.
Subject(s)
Animals , DNA, Mitochondrial/genetics , Deer/genetics , Microsatellite Repeats/genetics , Phylogeny , DNA, Mitochondrial/analysis , Deer/classification , Geography , Genetic Markers/geneticsABSTRACT
Objective To explore the relationship between mitochondrial DNA gene,GJB2 gene mutations and the susceptibility to noise-induced hearing loss in the army,and to provide scientific evidence for gene screening of susceptible individuals and relevant molecular epidemiology.Methods 182 blood samples were collected from 349 soldiers,consisting of susceptible and tolerance groups exposed to military noise in Beijing.Genomic DNA was isolated,and the targeted fragments of mitochondrial DNA and coding region of GJB2 gene were amplified by polymerase chain reaction(PCR).The PCR products were analyzed by direct sequencing.Results The results revealed that there were 98 mtDNA variants(41 reside in 12SrRNA) and 12 GJB2 gene variants;among them,mtDNA T1095C and G7642A coexisted in 4 susceptible individuals,but these mutations were not found in the tolerance group.In addition,3 tolerant individuals carried 961delT+insC while no one was found in the susceptible group.Conclusion The 12SrRNA is an area evidenced by high variant and mutation rate.The coexistence of mtDNA T1095C and G7642A in the susceptible group exposed to the similar noise suggests that these mutations are pathogenic mutations associated with NIHL.Three tolerant individuals with the history of long-term noise exposure carry 961delT+insC,suggesting that 961delT+insC might be a conditional pathogenic mutation,but not correlate with NIHL.
