DNA barcode de espécies raras de peixes da costa brasileira
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Data
2022-02-08
Autores
Maximiano, Loriane Pereira
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os oceanos abrangem cerca de 70% da superfície terrestre. Entretanto, pouco se sabe sobre a diversidades e aspectos genéticos da fauna marinha. A ausência de material em coleções zoológicas representativas e falta de estudos taxonômicos dificultam o reconhecimento da diversidade de peixes marinhos brasileiros, tendo como consequência comparações globais limitadas. Devido às dificuldades no reconhecimento da diversidade de peixes marinhos somente através de identificações morfológicas, técnicas moleculares vêm sendo desenvolvidas e utilizadas, dentre elas o DNA barcode, que consiste em um sistema diagnóstico universal, baseado em um fragmento de aproximadamente 650 pares de base do gene mitocondrial citocromo oxidase subunidade 1. Em nosso estudo utilizamos essa ferramenta para analisar espécies de peixes pouco comuns em coleções zoológicas, para contribuir com a formação de um banco de dados de sequências de espécies de peixes marinhos distribuídas ao longo da costa brasileira e compará-las com sequencias ao longo de sua distribuição. No total, 57 espécimes de 21 espécies, 18 gêneros, 13 famílias e 7 ordens tiveram seus fragmentos de DNA barcode amplificados por PCR e sequenciados. Os resultados foram apresentados em árvores de distâncias com o algoritmo Neighbor-Joining (NJ) e tiveram suas distâncias genéticas calculadas de acordo com o melhor modelo evolutivo sugerido para a análise, além da análise ABGD (Automatic Barcode Gap Discovery For Primary Species Delimitation). Nossos resultados geraram as primeiras sequências brasileiras em banco de dados para as espécies Echiophis intertinctus e Conger orbignyanus, e corroboram com a técnica de DNA barcode como ferramenta eficiente na identificação e discriminação de peixes da costa brasileira, bem como identificar possíveis casos de sinonimização e especiação desses indivíduos.
The oceans cover about 70% of the Earth's surface. Meanwhile, little is known about the diversity and genetic aspects of marine fauna. In the absence of representative zoological collections and taxonomic studies, it becomes difficult or reconstructive of the diversity existing in the Brazilian marine environment, resulting in limited global comparisons. Due to the difficulties, the diversity of marine fish is not reconciled through morphological identifications, molecular techniques that are being developed and used, within them or barcode DNA, which consists of a universal diagnosis system, based on a fragment of approximately 650 base pairs of the gene, mitochondrial cytochrome c oxidase subunit 1. In our study, we used this tool to analyze species of fish, few common in zoological collections, to contribute to the formation of a database of sequences of marine fish species distributed along the Brazilian coast and to compare the sequences in the long term. its distribution. Total number, 57 specimens of 21 species, 18 genera and 13 families and 7 orders had their barcode DNA fragments amplified by PCR sequenced. The results are presented in Neighbour-Joining (NJ) distance trees, and their genetic divergences are calculated according to the evolutionary model suggested for analysis. Our results generated the first brazilian sequences in a database for the species Echiophis intertinctus and Conger orbignyanus and corroborate the DNA barcode technique as an efficient fermentation in the identification and discrimination of fish off the Brazilian coast, as well as in the identification of possible cases of synonymization and speciation of individuals.
The oceans cover about 70% of the Earth's surface. Meanwhile, little is known about the diversity and genetic aspects of marine fauna. In the absence of representative zoological collections and taxonomic studies, it becomes difficult or reconstructive of the diversity existing in the Brazilian marine environment, resulting in limited global comparisons. Due to the difficulties, the diversity of marine fish is not reconciled through morphological identifications, molecular techniques that are being developed and used, within them or barcode DNA, which consists of a universal diagnosis system, based on a fragment of approximately 650 base pairs of the gene, mitochondrial cytochrome c oxidase subunit 1. In our study, we used this tool to analyze species of fish, few common in zoological collections, to contribute to the formation of a database of sequences of marine fish species distributed along the Brazilian coast and to compare the sequences in the long term. its distribution. Total number, 57 specimens of 21 species, 18 genera and 13 families and 7 orders had their barcode DNA fragments amplified by PCR sequenced. The results are presented in Neighbour-Joining (NJ) distance trees, and their genetic divergences are calculated according to the evolutionary model suggested for analysis. Our results generated the first brazilian sequences in a database for the species Echiophis intertinctus and Conger orbignyanus and corroborate the DNA barcode technique as an efficient fermentation in the identification and discrimination of fish off the Brazilian coast, as well as in the identification of possible cases of synonymization and speciation of individuals.
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Palavras-chave
Barcode, COI, DNA mitocondrial, Peixes