基于16S rRNA和Cyt b基因序列探讨2种梅童鱼的遗传分化  

Discussion of relationship between Collichthys lucidus and C. niveatus based on 16S rRNA and Cyt b gene sequences

作　　者：马国强[1] 高天翔[1] 孙典荣[2] 

机构地区：[1]中国海洋大学海水养殖教育部重点实验室,山东青岛266003 [2]中国水产科学研究院南海水产研究所,广东广州510300

出　　处：《南方水产》2010年第2期13-20,共8页South China Fisheries Science

基　　金：国家高技术研究发展计划(863计划)项目(2006AA09Z418);国家自然科学基金项目(30471329)

摘　　要：比较分析了棘头梅童鱼(Collichthys lucidus)和黑鳃梅童鱼(C.niveatus)的16SrRNA和Cytb基因片段序列差异及遗传分化程度。在长度为526bp的16S rRNA和379bp的Cytb基因片段的核苷酸序列中,2种间共检测到44处核苷酸替代。分析结果表明,2个基因片段的鸟嘌呤(G)含量较低,在Cytb蛋白质编码基因第三密码子位点上表现尤为明显。基于16S rRNA和Cytb基因片段分析结果显示,2种间平均遗传距离分别为0.012和0.111。构建的系统树显示2种梅童鱼在这2个基因片段上存在显著的遗传分化。根据Cytb基因2%/百万年的进化速率推断,棘头梅童鱼与黑鳃梅童鱼的分化时间约为550万年,发生于上新世(Pliocene)早期。Collichthys lucidus and C. niveatus are commercially important fishery resources in China. Partial nucleotide sequences of mitochondrial DNA 16S rRNA and Cyt b gene fragments were sequenced and analyzed to study the relationship between C. luc/dus and C. niveatus. Forty-four nucleotide substitutions were detected among 16S rRNA （526 bp） and Cyt b （379 bp） fragments. Nucleotide composition analysis indicated that the content of guanine （G） was relatively low in the two fragments, especially at the third codon position of Cyt b genes. Average genetic distances based on 16S rRNA and Cyt b between C. lucidus and C. niveatus were 0. 012 and 0. 111, respectively. The phylogenetic tree showed that there was significant genetic divergence between C. luc/dus and C. niveatus. According to the evolutionary rate of 2% per one million years, the estimated divergence time between C. luc/dus and C. niveatus was 5.5 million years, which indicated an early Pliocene divergence for them.

关 键 词：棘头梅童鱼 黑鳃梅童鱼 16S RRNA CYT b 遗传分化 

分 类 号：Q244[生物学—细胞生物学] Q522.6