军曹鱼的分子遗传特性研究

STUDIES ON MOLECULAR GENETIC CHARACTERISTICS OF COBIA RACHYCENTRON CANADUM

采用随机扩增多态性DNA(RAPD)和线粒体DNA(mtDNA)的限制性片段长度多态性(RFLP)分析方法对广东湛江近海军曹鱼 Rachycentron canadum 的分子遗传学特征进行了研究。RAPD研究结果显示 17 个引物共检测到 119 个位点,其中多态位点比例 P 为80.85%,遗传相似系数S为 0. 740 0,遗传距离 D 为 0. 260 0, Nei 基因多样性指数 H 为0.300 9,Shannon信息指数I为0.449 8。结果表明,军曹鱼的遗传多样性比较丰富。用 19种识别5、6碱基的限制性内切酶对军曹鱼的mtDNA RFLP进行了分析研究,构建其mtDNA物理图谱;用引物 5’ GTG ATC TGA AAA ACC ACC GTT G 3’和 5’ AAT AGG AAGTAT CAT TGC GGT TTG ATG 3’扩增线粒体细胞色素b区段,得到稳定的850bp大小的特异性条带,用18种识别4—6碱基的限制性内切酶对扩增片段的限制性长度多态性进行分析,并测定其序列。

Molecular genetic characteristics of cobia Rachycentron canadum was studied. Random amplified polymorhic DNA (RAPD) technique was used to investigate the genetic variation of natural population of cobia. Totally 119 loci were obtained with 17 primers. The percentage of polymorphic loci (P) was about 80.85% .The genetic distance (D) between the individuals was 0.2600 on average. The Nei's gene diversity index (H) was 0.3009 on average .The Shannon information index was 0.4498 on average. The results show that the nuclear genetic variability of cobia was comparatively rich. The restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA) of cobia was studied using 19 restriction endonucleases recognizing 5, 6 base pairs. The physical map of mtDNA has been constructed based on 6 endonucleases selected from 20 restriction endonucleases. A 850-bp segment of the mtDNA cytochrome b was amplified using primers like 5'-GTG ATC TGA AAA ACC ACC GTT G-3' and 5'-AAT AGG AAG TAT CAT TGC GGT TTG ATG-3'. The RFLP of mtDNA cytochrome b of cobia was studied using 18 restriction endonucleases recognizing 4-6 base pairs. The assay showed that the genetic marker was suitable for studies on cobia genetics and breeding.