鲤鱼遗传连锁图的研究

Molecular breeding is increasingly popular in studies on genetics and breeding in aquatic animals of economic importance. Genetic linkage analysis lays the groundwork for marker-assisted selection, quantitative trait loci (QTLs) identification and studies on evolution of animal genomes. Common carp (Cyprinus carpio) is one of the most traditional cultured freshwater fishes in China. Although intensive studies on genetics and breeding have been carried out for the past decades in both China and other countries, little is known to the characteristics of the carp genome. In this project, over 400 molecular markers of different kinds, mainly RAPD, SSR and AFLP, have been screened in various strains of carp. Double-locus amplification was found in some of the SSR markers, confirming a proposed tetraploidy origin of carp in the history. Sequence analysis of the fragments of mtDNA 16S rRNA and Cyto b genes suggested that genetic divergence among current Chinese carp strains may be quite recent. Some carp SSR loci have been successfully amplified and are polymorphic in species across genera or even subfamilies, which may be useful in genetic analysis for closely-related species in the family. Currently, analyses for some 200 markers of different types mainly in a backcross mapping family are in process with the aid of computer programs. A would-be genetic map of certain linkage groups is valuable for some aspects of molecular breeding in common carp. The methodologies and techniques derived from this project would also be useful to genetic linkage analysis of other cyprinid species. Financially supported by this project, four papers, including two appeared on SCI journals, have been published. Two other manuscripts are in preparation .

以鲤鱼为材料，通过诱导人工单性发育，在单倍体作图群体中检测微卫星、RAPD和AFLP等分子遗传标记的多态性；借助计算机软件进行遗传连锁分析，构建若干连锁群，获得鲤鱼的遗传连锁图。本研究结果将为鲤鱼基因组完整物理图谱以至全序列图谱的研制打下基础，在鱼类优良性状基因座位的分离等选育种研究中应用前景十分广阔。