利用线粒体 DNA Cytb 基因 PCR-RFLP 分析方法鉴别青鱼和草鱼

IDENTIFICATION OF MYLOPHARYNGODON PICEUS AND CTENOPHARYNGODON IDELLUS BY PCR -RFLP ANALYSIS OF MITOCHONDRIAL DNA Cyt b GENE

建立了一种以线粒体细胞色素 b（Cyt b）基因为标靶，应用 PCR -RFLP 技术进行草鱼和青鱼种质鉴定的分析方法。设计一对引物 QYCYT -S 和 QYCTY -A 分别对青鱼和草鱼的 Cyt b 基因进行了 PCR 扩增，并选用 BglⅠ和 EcoRⅡ两种限制性内切酶对扩增产物进行酶切分析。结果表明，草鱼和青鱼都可以扩增出1111 bp 的条带，两种酶切检验发现，草鱼扩增产物能被 BglⅠ切成247 bp 和864 bp 两个片段，而青鱼的 PCR 产物能被 EcoRⅡ切成140 bp 和971 bp 两个片段，这表明，mtDNA Cyt b 基因 BglⅠ和EcoRⅡ的酶切位点都可作为鉴定青鱼和草鱼的有效分子标记。利用 PCR -RFLP 分析 mtDNA Cyt b 基因的方法操作简单，是一种快速鉴别草鱼和青鱼的可靠方法。

A method to distinguish Mylopharyngodon piceus and Ctenopharyngodon idellus was developed based on the PCR-RFLP analysis of mitochondrial DNA（mtDNA）Cytb gene.A pair of PCR primers QYCYT-S and QYCYT-A was employed to amplify a fragment of mtDNA Cytb gene in Mylopharyngodon piceus and Ctenopharyngodon idellus.BglⅠand EcoR II restriction enzyme digestion analysis was further conducted against the PCR products.The results showed that a 1 1 1 1 bp long amplification fragment can be successfully abtained from both species.Restriction analysis showed that the amplification fragment from Mylopharyngodon piceus can be only restricted by Bgl I into two bands with the length of 247 bp and 864 bp,while the amplification fragment from Ctenopharyngodon idellus can be only restricted by EcoRⅡ into two bands with the length of 140 bp and 971 bp.The result suggests that the Bgl Ⅰand EcoR Ⅱ sensitive,restriction sites of mtDNA Cytb gene can be used as effective molecular identification markers between the two spicies of Mylopharyngodon piceus and Ctenopharyngodon idellus.This study demonstrated that the PCR -RFLP analysis of mtDNA Cytb gene is a rapid method to accurately distinguish the spicies of Mylopharyngodon piceus and Ctenopharyngodon idellus.