乌龟遗传多样性的RAPD分析

GENETIC DIVERSITY ANALYSIS OF CHINESE THREE-KEELED POND TURTLE (CHINEMYS REEVESII) BY RAPD

运用RAPD技术对乌龟的遗传多样性进行了分析。用 2 0个随机引物对 2 4个个体的基因组DNA进行了PCR扩增 ,一共扩增出 32 88条DNA片段 ,平均每个个体扩增出 137条带。在检测到的 137个位点中 ,多态位点数为 119个 ,占 86 9% ,标记的分子量在 0 .2kb— 3kb之间。个体间最大的遗传距离为 0 4 6 7,个体间最小的遗传距离为0 16 8。 2 4个个体的平均遗传距离为 0 32 4 +0 0 6 31。表明乌龟的遗传多样性水平较高。采用类平均聚类法(NJTREE)构建了 2 4个个体相互关系的分支图。 2 4个个体被分为几个类群 ,显示种内遗传差异较大 ,可能存在不同种群。本研究为乌龟的种质保护、合理开发利用以及选择育种提供了新的分析参数。

Chinese three-keeled pond turtle (Chinemys reevesii Gray) is a member of the family Emydidae and widely ranges in southern China, especially in the regions of the lower and middle Yangtze River. It has high values for food, traditional Chinese medicine and pet trade, and is one of the turtles for aquaculture in China. But the genetic background of Chinese three-keeled pond turtle is still not very clear. In order to realize its population genetic structure and the diversity for the conservation of its germ plasm and prevention of gene loss, genetic diversity analysis was carried out using RAPD-PCR technique. In this paper, genetic diversity of 24 individuals of Chinese three-keeled pond turtle from Hubei province was analyzed by the random amplified polymorphic DNA (RAPD) technique, using 20 10-nucleotide-long primers. Twenty primers produced 3288 well-amplified DNA fragments with reproducible banding patterns and averaged 137 DNA fragments in one individual. 119 of 137 loci detected are polymorphic, amounting to 86.9%. The DNA fragments were from 0.2kb to 3kb. The genetic distance between two individuals was from 0.168 to 0.467. The average genetic distance was 0.324±0.0631 among the 24 individuals. The phylogenetic tree of the 24 individuals was obtained by NJTREE analysis in the RAPDistance program and the 24 individuals were divided into several clusters and it indicated the turtle maybe have two populations at least. In conclusion, genetic diversity of Chinese three-keeled pond turtle was high.