Genetic diversity of northern snakehead (Channa argus) and albino northern snakehead from different regions unveiled by the mitochondrial DNA D-loop region

The sample collection information about four C. argus populations and three A. argus populations obtained from different geographical locations. The primers were designed using Primer 5.0 (Zhai et al., 2008). According to the full-length mitochondrial sequence of C. argus published in GenBank (accession number NC 015191.1), the upstream primers for the amplification of D-loop region sequences were 5¢-GCCTCTTTCCTTTACTTCTC-3¢, and the downstream primers were 5¢-GGGTGTATTGAGCCTGATA-3¢.The PCR products were bidirectionally sequenced by Sangon Biotech Co., Ltd. The D-loop sequences were separately aligned and trimmed to equal lengths using the MEGA 5.2 (Tamura et al., 2011) and ClustalX 2.1 (Thompson et al., 1997) software. Genetic diversity parameters were estimated using DnaSP 5.0 (Rozas et al., 2003) software. A Neighbor-joining (NJ) phylogenetic tree and the genetic distance among all the populations (the average genetic distances based on Kimura’s two-parameter model), and A UPGMA (Unweighted Pair Group Method with Arithmetic Mean) tree and the genetic distance among all the populations (the average genetic distances based on Tajima-Nei model) were constructed and computed using MEGA 5.2 software. Arlequin 3.5(Excoffier and Lischer, 2010) was used to calculate the nucleotide composition statistics, molecular analysis of variance (AMOVA), and genetic differentiation index (F-statistics, FST). Network 4.6 (Polzin and Daneshmand, 2003) was used to construct a haploid Reduced media-type (MJ) Network graph.

本数据集包含采自不同地理区域的4个C. argus种群与3个A. argus种群的样本采集相关信息。所用引物通过Primer 5.0软件（Zhai等，2008）设计得到。基于GenBank中已发表的C. argus全长线粒体序列（登录号NC 015191.1），用于扩增D-loop区序列的上游引物为5¢-GCCTCTTTCCTTTACTTCTC-3¢，下游引物为5¢-GGGTGTATTGAGCCTGATA-3¢。PCR产物由上海生工生物工程股份有限公司完成双向测序。使用MEGA 5.2（Tamura等，2011）与ClustalX 2.1（Thompson等，1997）软件对所有D-loop序列分别进行序列比对，并截齐至统一长度。采用DnaSP 5.0（Rozas等，2003）软件估算群体遗传多样性参数。借助MEGA 5.2软件构建邻接（Neighbor-joining, NJ）系统发育树，并计算基于Kimura双参数模型的所有种群间平均遗传距离；同时构建非加权配对算术平均法（Unweighted Pair Group Method with Arithmetic Mean, UPGMA）系统发育树，并计算基于Tajima-Nei模型的所有种群间平均遗传距离。使用Arlequin 3.5（Excoffier与Lischer，2010）计算核苷酸组成统计量、分子方差分析（Analysis of Molecular Variance, AMOVA）以及遗传分化指数（F统计量，FST）。通过Network 4.6（Polzin与Daneshmand，2003）构建单倍型简约中介（Reduced Median, MJ）网络图。