中华鲟随机扩增多态性DNA及遗传多样性研究

RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) AND GENETIC DIVERSITY OF CHINESE STULRGEON (ACIPENSER SINENSIS)

采用随机扩增多态性ＤＮＡ（ＲＡＰＤ）技术进行了连续３年（１９９５－１９９７）共７０尾来源于长江水系中华鲟样本遗传分析。共用了４０个 １０ｂｐ长的随机引物，在 ２６种可供分析的引物中，只有ＯＰＫ０１、ＯＰＫ０２、ＯＰＫ０３、ＯＰＫ０９、ＯＰＫ１４和ＯＰＱ０８ＲＡＰＤ－ＰＣＲ产物有多态现象，多态引物占２３％。２６个引物中共扩增出１０８条稳定的ＤＮＡ带。其中１２条带为多态带，多态座位比例为１１．１％。个体间遗传距离变动为０．９５１ ０－１．０００ ０，平均为０．９７４ ３。 １９９５、１９９６和１９９７年的遗传多样性指数（Ｈ）分别为０．０３２ ７、０．０３１２和 ０．０３５ ４。 ３年样本的综合遗传多样性指数（Ｈ）为０．０３３ ４。比较而言，中华鲟天然群体核ＤＮＡ水平的遗传多样性仍较低。

Chinese sturgeon (Acipenser sinensis), regarding as an 'living fossil', has a high value not only in science but also in commerce. However, duo to habitat destruction, overfishing and pollution etc. the resources abundance has been depleting. In order to monitor the change in resources and develop a sound management program studies on population structure and gene diversity is necessary. Our previous investigation using protein electrophoresis showed that genetic diversity of Chinese sturgeon at protein level was poor. In order to further address the genetic variability Random Amplified Polymorphic DNA (RAPD) was used to screen nuclear genome variation of natural population in Chinese sturgeon from the Yangtze River. Totally 70 samples were analyzed by RAPD, and among the 70 samples 40, 17, and 13 samples were collected from year 1995, 1996, and 1997, respectively. 40 decamer primers were applied for analysis and only 26 primer gave stable result. Among 26 primers studied only 6 primers (23%) such as OPK01, OPK02, OPK03, OPK09, OPK14 and OPQ08 produced polymorphic bands. Total 108 bands (locus) were obtained by using 26 primers. A Primer Produced 4.2 bands on average. Out of the 108 bands (locus), 12 bands are polymorphic and percentage of polymophic loci (P) was about 11.1%. Denetic distance between individuals is 0.974 3 on average, ranging from 0.951 0 to 1.000 0. The genetic diversity H= N which was derived from Shannon's index of phenotypic diversity H = were introduced. Total genetic diversity from three year-pooled samples was 0.033 4. The genetic diversity for year 1995, 1996 and 1997 were 0.032 7,0.031 2 and 0.035 4, respechvely. Comparatively, the nuclear genome variability is poor, consistent with the data obtained from protein electrophoresis. The low genetic variability at nuclear level might take place a long time ago. The construction of the Gezhouba dam on the Yangtze River is not a reason for low genetic variation at nuclear genome because the individuals studied were born before the damming.