Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Zootaxa ; 4758(1): zootaxa.4758.1.6, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32230158

RESUMO

We describe a new species of turtle-headed sea snake Emydocephalus orarius sp. nov. (Elapidae) from Western Australia's Coral Coast, Pilbara and Kimberley regions. Phylogenetic analysis of mitochondrial markers places the new species as the sister lineage to the two currently recognised species in Emydocephalus: E. annulatus from the Timor Sea reefs and Coral Sea, and E. ijimae from the Ryukyu Islands. Analysis of nuclear SNP data from the new species and E. annulatus from Australia and New Caledonia provides additional independent evidence of their evolutionary distinctiveness. The new taxon is usually morphologically diagnosable from its congeners using a combination of scalation and colour pattern characters, and appears to reach greater total lengths (>1 m in the new species versus typically ~80 cm in E. annulatus/E. ijimae). The new species is known largely from soft-bottomed trawl grounds, unlike E. annulatus and E.ijimae which usually inhabit coral reefs. The discovery of this new species brings the number of sea snake species endemic to Western Australia to six.


Assuntos
Hydrophiidae , Animais , Hydrophiidae/classificação , Filogenia , Austrália Ocidental
2.
Biol Lett ; 14(10)2018 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-30333264

RESUMO

Comparative phylogeography can inform many macroevolutionary questions, such as whether species diversification is limited by rates of geographical population differentiation. We examined the link between population genetic structure and species diversification in the fully aquatic sea snakes (Hydrophiinae) by comparing mitochondrial phylogeography across northern Australia in 16 species from two closely related clades that show contrasting diversification dynamics. Contrary to expectations from theory and several empirical studies, our results show that, at the geographical scale studied here, rates of population differentiation and speciation are not positively linked in sea snakes. The eight species sampled from the rapidly speciating Hydrophis clade have weak population differentiation that lacks geographical structure. By contrast, all eight sampled Aipysurus-Emydocephalus species show clear geographical patterns and many deep intraspecific splits, but have threefold slower speciation rates. Alternative factors, such as ecological specialization, species duration and geographical range size, may underlie rapid speciation in sea snakes.


Assuntos
Especiação Genética , Hydrophiidae/classificação , Hydrophiidae/genética , Filogeografia , Animais , Austrália , Citocromos b/genética , DNA Mitocondrial/genética , Genética Populacional , Análise de Sequência de DNA , Especificidade da Espécie
3.
Int J Mol Sci ; 18(12)2017 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-29231898

RESUMO

The spine-bellied sea snake (Hydrophis curtus) is known to cause human deaths, yet its venom composition has not yet been proteomically characterised. An indepth proteomic analysis was performed on H. curtus venom from two different seasons, January and June, corresponding to adults and subadults, respectively. Venoms from adult and subadult H. curtus individuals were compared using reversedphase high-performance liquid chromatography (RP-HPLC), matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry and liquid chromatography electrospray ionisation mass spectrometry (LC-ESI-MS) to detect intraspecific variation, and the molecular weight data obtained with ESIMS were used to assess toxin diversity. RPHPLC and LCESIMS/MS were used to characterise the venom proteome and estimate the relative abundances of protein families present. The most abundant protein family in January and June venoms is phospholipase A2 (PLA2: January 66.7%; June 54.5%), followed by threefinger toxins (3FTx: January 30.4%; June 40.4%) and a minor component of cysteine-rich secretory proteins (CRISP: January 2.5%; June 5%). Trace amounts of snake venom metalloproteinases (SVMP), C-type lectins and housekeeping and regulatory proteins were also found. Although the complexity of the venom is low by number of families present, each family contained a more diverse set of isoforms than previously reported, a finding that may have implications for the development of next-generation sea snake antivenoms. Intraspecific variability was shown to be minor with one obvious exception of a 14,157-Da protein that was present in some January (adult) venoms, but not at all in June (subadult) venoms. There is also a greater abundance of short-chain neurotoxins in June (subadult) venom compared with January (adult) venom. These differences potentially indicate the presence of seasonal, ontogenetic or sexual variation in H. curtus venom.


Assuntos
Venenos Elapídicos/metabolismo , Hydrophiidae/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Toxinas Biológicas/metabolismo , Animais , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Hydrophiidae/classificação , Espectrometria de Massas/métodos , Fosfolipases A2/metabolismo , Estações do Ano , Especificidade da Espécie
4.
Zhongguo Zhong Yao Za Zhi ; 41(10): 1792-1796, 2016 May.
Artigo em Chinês | MEDLINE | ID: mdl-28895322

RESUMO

Hydrophidae, one of the precious traditional Chinese medicines, is generally drily preserved to prevent corruption, but it is hard to identify the species of Hydrophidae through the appearance because of the change due to the drying process. The identification through analysis on gene barcode, a new technique in species identification, can avoid this problem. The gene barcodes of the 5 species of Hydrophidae, Lapemis hardwickii, Hydrophis fasciatus, Aipysurus eydouxii, Hydrophis belcher and Hydrophis lamberti, were acquired through DNA extraction and gene sequencing. These barcodes were then in sequence alignment and test the identification efficiency by BLAST. Our results showed that the 16S rDNA sequences identified Hydrophidae briefly and the COI sequenceshad obvious difference between intra-and inter-species, indicating that DNA bar-coding was an efficiency method of Hydrophidae identification.


Assuntos
Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons/genética , Hydrophiidae/classificação , Animais , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA