THE GH GENE DIVERSITY AMONG THREE SINIPERCA FISH SPECIES
三种鳜鱼(Siniperca)生长激素基因内含子多态性的比较研究

Siniperca chuatsi, S. kneri, S. schezeri are three major commercial fish species in genus Siniperca; they have close relationships and similar life habits, but significantly different growth. To understand the reason, the diversity of GH genes of three members is studied using PCR amplification, electrophoresis, and sequencing. Sequence diversities were observed in Intron 1, forepart of Intron 2, and microsatellite sites in Intron 2 and Intron 3. Twenty-five length types have been observed in all regions, among them 4 types are shared by S. chuatsi and S. kneri, and 3 types shared by three fishes; others were species-specific. All the length types in different regions formed 14 haplotypes, being species-specific. The sequence diversities are mainly due to repeat sequences and inserts or deletions of DNA fragments. There were two diversity loci close to the 3'-acceptor splice site of Intron 1 and the 5'-donor splice site of Intron 3 respectively. Phylogenetic tree was constructed based on diversity detections. S. chuatsi and S. kneri cluster into one clade before join S. schezeri. All these findings have laid a foundation for further study on the relationship between gene diversity and trait difference, as well as for further utilization of the diversity of GH gene in molecular breeding and germplasm conservation of the Siniperca fishes.