Identification, Discrimination, and Discovery of Species of Marine Planktonic Ostracods Using DNA Barcodes.
Identification, Discrimination, and Discovery of Species of Marine Planktonic Ostracods Using DNA Barcodes.
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DOI：
10.1371/journal.pone.0146327
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Bucklin A
中科院分区：
文献类型：
--
作者：
Nigro LM;Angel MV;Blachowiak-Samolyk K;Hopcroft RR;Bucklin A
介形虫（甲壳纲；介形虫纲）是海洋浮游动物群落中种类繁多、数量丰富且具有重要生态意义的组成部分。目前已知的海洋浮游介形类有200多种，其中许多（特别是同种）只能通过显微镜检查和解剖脆弱的形态特征来识别。鉴于物种鉴定的复杂性和分类专家的日益缺乏，DNA条形码（用于物种鉴别和鉴定的短DNA序列）特别有用和必要。本文报道了对78种海洋浮游介形类210个标本的分析结果，其中包括2种新种和51种以前未发表过条形码的标本。2006年至2008年期间，在大西洋、印度洋和南大洋、格陵兰海和阿拉斯加湾收集了标本。使用各种收集装置从表面到5,000 m处收集样品。分析了线粒体细胞色素氧化酶亚基I （COI）基因598碱基对区域的DNA序列变异。除8个因形态差异（尤其是大小差异）和/或来自不同地理区域而被推测为隐种的类群外，所述种间的Kimura-2-Parameter遗传距离（平均值= 0.010±0.017 SD）显著小于种间的K2P遗传距离（0.260 + 0.080）。在（0.014 + 0.026）种间和（0.221±0.068）种间K2P距离值相近。所有的K2P距离>.1都来自于已鉴定种和隐种之间的比较，种内和种间的遗传距离没有重叠。邻居连接树几乎解决了所有被分析的物种，多个序列形成了具有高bootstrap值（通常为99%）的单系聚类。基于分类和地理上广泛的采样和分析（尽管样本量很小），COI条形码区域被证明是海洋浮游介形类物种鉴别、识别、鉴定和发现的一个有价值的特征。
The Ostracoda (Crustacea; Class Ostracoda) is a diverse, frequently abundant, and ecologically important component of the marine zooplankton assemblage. There are more than 200 described species of marine planktonic ostracods, many of which (especially conspecific species) can be identified only by microscopic examination and dissection of fragile morphological characters. Given the complexity of species identification and increasing lack of expert taxonomists, DNA barcodes (short DNA sequences for species discrimination and identification) are particularly useful and necessary. Results are reported from analysis of 210 specimens of 78 species of marine planktonic ostracods, including two novel species, and 51 species for which barcodes have not been previously published. Specimens were collected during 2006 to 2008 from the Atlantic, Indian, and Southern Oceans, Greenland Sea and Gulf of Alaska. Samples were collected from surface to 5,000 m using various collection devices. DNA sequence variation was analyzed for a 598 base-pair region of the mitochondrial cytochrome oxidase subunit I (COI) gene. Kimura-2-Parameter (K2P) genetic distances within described species (mean = 0.010 ± 0.017 SD) were significantly smaller than between species (0.260 + 0.080), excluding eight taxa hypothesized to comprise cryptic species due to morphological variation (especially different size forms) and/or collection from different geographic regions. These taxa showed similar K2P distance values within (0.014 + 0.026) and between (0.221 ± 0.068) species. All K2P distances > 0.1 resulted from comparisons between identified or cryptic species, with no overlap between intra- and interspecific genetic distances. A Neighbor Joining tree resolved nearly all described species analyzed, with multiple sequences forming monophyletic clusters with high bootstrap values (typically 99%). Based on taxonomically and geographically extensive sampling and analysis (albeit with small sample sizes), the COI barcode region was shown to be a valuable character for discrimination, recognition, identification, and discovery of species of marine planktonic ostracods.