中国对虾(Fenneropenaeus chinensis)与生长性状相关SCAR标记的筛选

GROWTH TRAITS RELATED SCAR MARKERS IN FENNEROPENAEUS CHINENSIS

采用RAPD技术对“黄海1号”中国对虾快速生长选育群体第6代大个体群体(CP-a)和小个体群体(CP-b)以及野生群体(WP)为对照组的各50尾个体进行扩增,获得可能与生长性状相关的9个RAPD遗传标记。对获得的标记进行克隆、测序并根据序列设计特异性引物对3个群体进行SCAR标记分析。其中6对引物(SCAR1、SCAR2、SCAR3、SCAR4、SCAR5和SCAR6)在3个群体中有扩增产物,前4对引物在3个群体共150尾个体中的扩增产物无多态性。SCAR5和SCAR6在3个群体中的扩增产物具有多态性。依据扩增产物在群体中出现的频率和变化规律进行分析表明,SCAR5扩增的多态片段在3个群体中的组成比例分别为78%、52%和54%,差异显著(P<0.05);SCAR6扩增的多态片段经电泳后产生3个等位基因,6种基因型,只有CP-b含有等位基因A。这2个标记可以作为与中国对虾生长性状相关的候选标记,为在生产实践中实行分子标记辅助育种奠定理论基础。

Overfishing for Fenneropenaeus chinensis （Chinese prawn ）in recent years has caused serious problems in the great shortage of supply of quality breeds,which has become a serious issue holding the aquiculture from sustainable developing. For the solution, fast-growing and strong anti-disease breeds should be sought. We conducted this research in November 2002 by sampling 150 individuals of the species for Random Amplified Polymorphic DNA （RAPD） study from three groups of 50 ; and the lab working began in January 2003. Among the three groups,two were taken from the 6th generation of Huanghai-I cultured F. chinensis,including the two extremes of size：large group in length 〉 15cm（CP-a） and small one in lengths 〈 llcm（ CP- b） ,and the third group were combined by wild ones in size between 11 and 14cm（WP）. For each group,240 random primers were screened for mixed templates. 65 growth trait correlated differential fragments were obtained,55 positive and 10 negative. Population analysis for the screened primers from 240 RAPD primers showed 9 RAPD primers were correlated to the growth traits,7 positive and 2 negative. After cloning and sequencing,8 sequences in length from 500bp to 1000bp were obtained except the marker amplified by S159. Using Premier 5 for designing specific primers and Sequence-Characterized Amplified Regions（SCAR） technique, growth traits markers of F. chinensis were determined. 6 SCARs （SCAR1-6） were amplifiable, among which the first four could not differentiate among the three populations,and the latter two could amplify polymorphic fragments in band frequency and variety rule shown in the samples. The number of polymorphic fragments amplified by primer SCAR5 in CP-a,CP-b and WP was 39,26 and 27,respectively,and the band frequency was 78% ,52% and 54% ,respectively.x^2 test of polymorphic fragments in CP-a and WP populations showed significantly difference（P 〈 0.05 ）, indicating that the polymorphic fragment can be used as positive marker candidate. 3 alleles and 6 genotypes were found in three populations amplified by primer SCAR6,while in CP-b allele A only,showing that locus A was probably related to certain genes that can restrain the growth of the prawn. The results are useful in breed-selection for production enhancement of F. chinensis applying marker-assisted selection （MAS） procedure.