Laboratório de Biologia e Genética de Peixes, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil.
Mol Ecol Resour. 2012 Nov;12(6):1012-20. doi: 10.1111/1755-0998.12007. Epub 2012 Sep 8.
Anthropogenic impacts are an increasing threat to the diversity of fishes, especially in areas around large urban centres, and many effective conservation actions depend on accurate species identification. Considering the utility of DNA barcoding as a global system for species identification and discovery, this study aims to assemble a DNA barcode reference sequence library for marine fishes from the coastal region of São Paulo State, Brazil. The standard 652 bp 'barcode' fragment of the cytochrome c oxidase subunit I (COI) gene was PCR amplified and bidirectionally sequenced from 678 individuals belonging to 135 species. A neighbour-joining analysis revealed that this approach can unambiguously discriminate 97% of the species surveyed. Most species exhibited low intraspecific genetic distances (0.31%), about 43-fold less than the distance among species within a genus. Four species showed higher intraspecific divergences ranging from 2.2% to 7.6%, suggesting overlooked diversity. Notably, just one species-pair exhibited barcode divergences of <1%. This library is a first step to better know the molecular diversity of marine fish species from São Paulo, providing a basis for further studies of this fauna - extending the ability to identify these species from all life stages and even fragmentary remains, setting the stage for a better understanding of interactions among species, calibrating the estimations about species composition and richness in an ecosystem, and providing tools for authenticating bioproducts and monitoring illegal species exploitation.
人为影响是鱼类多样性面临的日益严重的威胁，特别是在大型城市中心周围的地区，许多有效的保护措施都依赖于准确的物种鉴定。考虑到 DNA 条码作为一种全球物种鉴定和发现系统的实用性，本研究旨在为巴西圣保罗州沿海地区的海洋鱼类建立一个 DNA 条码参考序列文库。从属于 135 个物种的 678 个个体中，PCR 扩增并双向测序了标准的 652bp '条码'片段细胞色素 c 氧化酶亚基 I（COI）基因。邻接法分析表明，这种方法可以明确区分 97%的调查物种。大多数物种的种内遗传距离较低（0.31%），约为属内种间距离的 43 倍。有 4 个种表现出较高的种内分化，范围从 2.2%到 7.6%，表明存在被忽视的多样性。值得注意的是，只有一对种表现出小于 1%的条码分化。该文库是更好地了解圣保罗海洋鱼类物种的分子多样性的第一步，为进一步研究该动物群提供了基础——扩展了从所有生命阶段甚至是碎片中识别这些物种的能力，为更好地了解物种之间的相互作用、校准对生态系统中物种组成和丰富度的估计以及为生物制品的认证和监测非法物种开发提供工具。
