青鱼线粒体ND4L的SNP筛选及在两种体色群体中的分布

为了分析青鱼线粒体蛋白编码基因与体色性状的相关性,从而筛选出与体色相关的SNP分子标记。本研究选取了5尾广东佛山灰色青鱼和5尾扬州邗江正常体色黑色青鱼群体的皮肤组织,通过qPCR检测13个线粒体蛋白质编码基因在两种颜色群体皮肤组织中的表达量,并进行显著性分析。对表达差异最明显的蛋白编码基因CDS区序列设计引物,并选取78尾佛山灰色青鱼样本和92尾邗江黑色青鱼样本进行测序,根据测序峰图筛选出SNP位点。结果发现：13个线粒体蛋白质编码基因中COII基因表达量最高,ND5基因表达量最低,ND4L基因在两种体色青鱼中的表达差异最为明显。在对170尾青鱼样本的线粒体ND4L基因上共检测到了2个SNP位点,位于编码区,且都为同义突变。卡方检验表明,252bp(C/T)处的SNP位点在两种体色青鱼群体中的等位基因频率和基因型频率都有极显著的差异(p＜0.01),243bp(A/G)处的SNP位点在两种体色青鱼群体中的等位基因频率和基因型频率差异不显著(p＞0.05),因此线粒体ND4L基因中的SNP位点C252T与青鱼体色显著相关。本研究中成功找到一个与青鱼体色相关的SNP分子标记,可以在青鱼的养殖和育种中提供理论分子层面的指导和帮助。

Screening of SNP markers of mitochondrial ND4L gene in black carp (Mylopharyngodon piceus) and their frequencies in two different body color populations

In order to analyze the association between mitochondrial protein-coding genes and body color traits of black carp, SNP markers related to body color were screened out. In this study, the skin tissues of five Foshan gray black carp samples and five Hanjiang black black carp samples were selected. The expression of 13 mitochondrial protein-coding genes in the skin tissues of the two color populations was detected by qPCR, and then the significance analysis was performed. We designed primers for the CDS region sequence of the protein-coding gene with the most obvious expression difference, and then selected 78 Foshan gray black carp samples and 92 Hanjiang black black carp samples for sequencing, and screened out SNP markers based on the sequencing peak map. The results showed that among the 13 mitochondrial protein coding genes, the expression of ND4L gene was the most significant, the expression of COII gene was the highest, and the expression of ND5 gene was the lowest. A total of 2 SNP sites were detected in the mitochondrial ND4L gene of 170 black carp samples, located in the coding region, and all of them were synonymous mutations. Chi-square test showed that the allele frequency and genotype frequency of SNP at 252bp(C/T) were extremely significantly different between the two black carp populations (p < 0.01), while the allele frequency and genotype frequency of SNP at 243bp(A/G) were not significantly different between the two black carp populations (p > 0.05), so the SNP marker C252T in the mitochondrial ND4L gene was significantly associated with black carp body color. In this study, we successfully found a SNP marker related to the body color of black carp, which can provide theoretical molecular guidance and help in the breeding of black carp.