ABSTRACT
Molecular appraoch for identification of unknown species by using Cytochrome b gene is an effective and reliable as compared with morphological based identification. For DNA barcoding universal molecular genes were used to identify the species. Cytochrome b is a specific gene used for identification purpose. DNA barcoding is a reliable and effective method compared to the different traditional morphological methods of specie identification. So,in the present study which was conducted to identify the species, a total of 50 fish samples were collected from five different sites. DNA was extracted by using the Phenol Chloroform method from muscle tissue. Five sequences were sequenced (one from each site), analyzed, and identified specific species as Pangasius pangasius. Identified sequences were variable in length from 369 bp (Site 1), 364 bp (Site 2), 364 bp (Site 3), 352 bp (Site 4), and 334 bp (Site 5). Identity matches on the NCBI database confirmed the specific specie as P. pangasius. A distancing tree was drawn to show maximum likelihood among the same and different species. Yet, in many cases fishes on diverse development stages are difficult to identify by morphological characters. DNA-based identification methods offer an analytically powerful addition or even an alternative tool for species identification and phylogenetic study. This work intends to provide an updated and extensive overview on the DNA based methods for fish species identification by using Cytochrome b gene as targeted markers for identification purpose.
A abordagem molecular para identificação de espécies desconhecidas usando o gene citocromo b é eficaz e confiável em comparação com a identificação baseada na morfologia. Códigos de barras de DNA de genes moleculares universais foram usados ââpara identificar as espécies. O citocromo b é um gene específico usado para fins de identificação. O código de barras de DNA é um método confiável e eficaz em comparação com os diferentes métodos morfológicos tradicionais de identificação de espécies. Assim, no presente estudo, que foi realizado para identificar as espécies, um total de 50 amostras de peixes foram coletadas em cinco locais diferentes. O DNA foi extraído usando o método Fenol Clorofórmio do tecido muscular. Cinco sequências foram sequenciadas (uma de cada local), analisadas e identificadas espécies específicas, como Pangasius pangasius. As sequências identificadas tinham comprimento variável de 369 bp (Local 1), 364 bp (Local 2), 369 bp (Local 1), 364 bp (Local 3), 352 bp (Local 4) e 334 bp (Local 5). As correspondências de identidade no banco de dados do NCBI confirmaram a espécie específica como P. pangasius. Uma árvore de distanciamento foi desenhada para mostrar a máxima probabilidade entre elas e diferentes espécies. No entanto, em muitos casos, peixes em diversos estágios de desenvolvimento são difíceis de identificar por caracteres morfológicos. Os métodos de identificação baseados em DNA oferecem uma adição analiticamente poderosa ou mesmo uma ferramenta alternativa para identificação de espécies e estudo filogenético. Este trabalho pretende fornecer uma visão geral atualizada e abrangente sobre os métodos baseados em DNA para identificação de espécies de peixes usando o gene citocromo b como marcadores direcionados para fins de identificação.
Subject(s)
Animals , Phylogeny , Cytochromes b , Biodiversity , FishesABSTRACT
Molecular appraoch for identification of unknown species by using Cytochrome b gene is an effective and reliable as compared with morphological based identification. For DNA barcoding universal molecular genes were used to identify the species. Cytochrome b is a specific gene used for identification purpose. DNA barcoding is a reliable and effective method compared to the different traditional morphological methods of specie identification. So,in the present study which was conducted to identify the species, a total of 50 fish samples were collected from five different sites. DNA was extracted by using the Phenol Chloroform method from muscle tissue. Five sequences were sequenced (one from each site), analyzed, and identified specific species as Pangasius pangasius. Identified sequences were variable in length from 369 bp (Site 1), 364 bp (Site 2), 364 bp (Site 3), 352 bp (Site 4), and 334 bp (Site 5). Identity matches on the NCBI database confirmed the specific specie as P. pangasius. A distancing tree was drawn to show maximum likelihood among the same and different species. Yet, in many cases fishes on diverse development stages are difficult to identify by morphological characters. DNA-based identification methods offer an analytically powerful addition or even an alternative tool for species identification and phylogenetic study. This work intends to provide an updated and extensive overview on the DNA based methods for fish species identification by using Cytochrome b gene as targeted markers for identification purpose.