舟山海域4种鲷科鱼类线粒体Cytb基因全序列克隆分析

Cloning and sequence analysis of Cyt b gene in four Sparidae fishes in Zhoushan sea area

克隆测序了分布于舟山海域的真鲷(Pagrus pagrus)、黑鲷(Sparus macrocephalus)、黄鳍棘鲷(Acanthopagrus latus)和二长棘鲷(Parargyrops edita)4种鲷科鱼类的线粒体Cyt b基因1141bp的全序列。通过对4种鲷科鱼类Cytb基因序列的比对分析,发现了292个核苷酸变异位点,其中存在186个信息位点,序列中的转换大于颠换,碱基替换多发生于密码子第3位。遗传距离分析表明,4种鲷科鱼类的遗传差异在0.0967～0.2275之间,其中真鲷与二长棘鲷之间遗传距离最小,为0.0967,黄鳍棘鲷与二长棘鲷的遗传距离最大,为0.2275;序列变异的转换/颠换比值在2.2930～7.3587之间。以25种鲈总科鱼类构建的系统树表明鲷科鱼类与其他科的鱼类存在较远的遗传亲缘关系。

The complete sequences of mitochondrial Cyt b gene in Pagrus pagrus, Sparus macrocephalus, Acanthopagrus latus and Parargyrops edita in Zhoushan sea area were amplified, cloned and sequenced. The 1 141 bp Cyt b gene sequences of these four species were obtained. Compared with the same DNA fragment recorded in the GeneBank, the sequences of 1 141 bp DNA had 292 nucleotide variation sites, among which 186 parsimony informative sites were observed. Transitions were discovered to be more than transversions, and most of the base substitutions occurred at the third locus of the eodon. The genetic distance among 4 Sparidae species ranged from O. 096 7 to 0. 227 5. The shortest distance occurred between P. pagrus and P. edita, being 0. 096 7, while the longest one between S. macrocephalus and A. latus, being 0. 227 5. Moreover, the transition-transversion ratio of the sequence differentiation of 4 species ranged from 2. 293 0 to 7. 358 7. The NJ phylogenetic tree revealed that 25 species were divided into two clades, and obvious genetic divergence existed between fishes of Sparidae and the other fishes of Percoidea.