Data for: Species identification and population genetics of the Antarctic fish genera Lepidonotothen and Nototheniops (Perciformes, Notothenioidei)

Accurate species identification is essential to assess biodiversity and species richness in ecosystems threatened by rapid and recent environmental changes, such as warming in most Antarctic waters. The Lepidonotothen species complex comprises demersal notothenioid fishes which inhabit the shelf areas of the Antarctic Peninsula, the Scotia Arc and sub-Antarctic islands with a circum-Antarctic distribution. Species determination in this group has often been problematic. In particular, whether Lepidonotothen squamifrons and Lepidonotothen kempi are valid as separate species has been questioned. In this study, we analysed the genetic variation among four nominal southern polar species within this complex (L. kempi, L. squamifrons, Nototheniops larseni, Nototheniops nudifrons) by means of three different markers (ND2 and tRNA mitochondrial genes and a panel of 16 nuclear microsatellites). We tested whether individuals morphologically assigned to L. kempi showed genetic separation from L. sq..., Mitochondrial markers:Â A 1,247 bp long mitochondrial fragment containing the entire ND2 gene and the upstream (trnM) and downstream (trnW and trnA) tRNAs was amplified with the primers GLN 5'-CTACCTGAAGAGATCAAAAC-3' and ASN 5'-CGCGTTTAGCTGTTAACTAA-3' following Kocher et al. (1995). The mitochondrial sequences were trimmed, assembled and cut to isolate the portion of ND2 (1041 bp) from the tRNAs. The sequence was revised by eye when necessary, by two operators using the software MacVector ver. 12.6 (Rastogi, 2000). Molecular validation with ND2 of morphological species identification was performed by querying every sample against the GenBank database with the Blastn and Blastp algorithms (Altschul et al., 1990). To check for presence of stop codons, nucleotide sequences were translated into aminoacids with the ExPASy translate tool (Gasteiger, 2003), resulting in a length of 347 amino acids. The sequences of the trnA, trnM and trnW were manually aligned together with all orthologs availa..., All files can be opened with a common text editor.精准的物种鉴定是评估受近期快速环境变化（如多数南极海域暖化）威胁的生态系统中生物多样性与物种丰富度的必要前提。勒氏南极鱼属（Lepidonotothen）物种复合群包含底栖性南极鱼亚目鱼类，其呈环南极分布，栖息于南极半岛、斯科舍弧（Scotia Arc）及亚南极岛屿的陆架区域。该类群的物种鉴定长期存在难题，其中尤以鳞鳍勒氏南极鱼（Lepidonotothen squamifrons）与肯普氏勒氏南极鱼（Lepidonotothen kempi）是否为独立有效物种这一问题备受质疑。 本研究针对该复合群内4个已命名的南极高纬度物种（L. kempi、L. squamifrons、拉尔森新南极鱼（Nototheniops larseni）、裸腹新南极鱼（Nototheniops nudifrons)），借助3类分子标记开展遗传变异分析，分别为ND2（烟酰胺腺嘌呤二核苷酸脱氢酶亚基2）基因与tRNA（转运RNA）线粒体基因，以及由16个核微卫星位点组成的位点组合。本研究旨在验证形态学鉴定为L. kempi的个体是否与L. sq...存在遗传分化。 线粒体标记：参照Kocher等人（1995）的方法，使用引物GLN 5'-CTACCTGAAGAGATCAAAAC-3'与ASN 5'-CGCGTTTAGCTGTTAACTAA-3'扩增一段长度为1247 bp的线粒体片段，该片段包含完整的ND2基因，以及上游的trnM基因与下游的trnW、trnA基因。研究团队对线粒体序列进行剪切、拼接与切割操作，以分离出长度为1041 bp的ND2基因片段（剔除tRNA区域）。必要时由两名操作者借助MacVector v12.6软件（Rastogi, 2000）进行人工序列校正。 为验证基于形态学的物种鉴定结果，本研究利用ND2基因序列，通过Blastn与Blastp算法（Altschul et al., 1990）将所有样本序列与GenBank数据库进行比对。为检测终止密码子的存在，使用ExPASy翻译工具（Gasteiger, 2003）将核苷酸序列翻译为氨基酸序列，最终得到长度为347个氨基酸的肽段。trnA、trnM与trnW的序列与所有可获取的直系同源序列进行人工联配，相关序列availa...。 所有文件均可通过通用文本编辑器打开。