5种七彩神仙鱼5S rDNA序列的比较

Sequence Analysis of 5S rDNA in 5 Strains of Discus Fish Symphysodon

采集鳍条,设计引物,提取了5种(黑格尔、盖子红、鸽子红、天子蓝、红点绿)七彩神仙鱼(Symphysodon)的5S r DNA,分析了其序列。结果表明:5种七彩神仙鱼均具有201 bp和401 bp 5S r DNA结构单元,而黑格尔(野生)、盖子红和鸽子红分别具有300,299,338 bp 5S r DNA结构单元。其编码区高度保守,而非转录间隔区差异显著,特别是黑格尔(野生)300 bp、盖子红299 bp和鸽子红338 bp的非转录间隔区。5种七彩神仙鱼G+C碱基的含量很高。红点绿、盖子红、鸽子红和天子蓝4个人工品种与野生品种黑格尔的亲缘关系分别为97.53%、90.12%、88.89%和85.19%,其中红点绿与黑格尔的亲缘关系最近。

The 5S r DNA was extracted and sequenced in fin rays of 5 strains of discus fish Symphysodon by designed primers. The results showed that the five discus all had the structural unit in 5S r DNA of 201 bp and 401 bp. However,the structural units of 300 bp,299 bp and 338 bp with high conservative coding regions were observed in the Heckel Discus（ the wild one）,Solid Red Discus and Pigeon Blood Discus. There were significant differences in non-transcribed spacer regions,especially the 300 bp in Heckel Discus（ wild）,the 299 bp in Solid Red Discus and the 338 bp in Pigeon Blood Discus. There was very high G＋C base content in these discus. The wild discus Heckel Discus showed genetic affinity rate of 97. 53% with Red Spotted Green Discus,90. 12% with Solid Red Discus,88.89% with Pigeon Blood Discus and 85.19% with Royal Blue Discus,and the maximal genetic affinity rate in Red Spotted Green Discus.