牙鲆和半滑舌鳎5S rDNA基因的染色体定位及鲽形目5种鱼类的分子系统学分析  

Chromosome mapping of 5S rDNA in olive flounder (Paralichthys olivaceus) and half-smooth tongue-sole (Cynoglossus semilaevis) and molecular systematics analysis of five flatfishes

作　　者：谢明树[1,2] 孙冰[1,2] 张博[1] 邵长伟[2] 王启龙[2] 王磊[2] 陈松林[2] 

机构地区：[1]大连海洋大学水产与生命学院,辽宁大连116023 [2]中国水产科学研究院黄海水产研究所,山东青岛266071

出　　处：《水产学报》2012年第8期1159-1166,共8页Journal of Fisheries of China

基　　金：公益性行业(农业)科研专项(200903046);山东省泰山学者工程专项

摘　　要：利用荧光原位杂交(FISH)技术将5S rDNA基因定位在牙鲆和半滑舌鳎染色体上,结果表明,5S rDNA基因在雌、雄性半滑舌鳎的一对同源染色体上分别存在2个杂交信号位点;在二、三倍体牙鲆的同源染色体上分别存在2个和3个杂交信号位点,杂交信号明显且特异。本研究首次将5S rDNA基因定位在半滑舌鳎和三倍体牙鲆的染色体上,为牙鲆及半滑舌鳎倍性鉴定、染色体鉴别提供了有效方法。此外,根据牙鲆5S rDNA基因编码区序列设计引物,扩增出大菱鲆和半滑舌鳎5S rDNA基因编码区序列,与鲽、塞内加尔鳎、大口黑鲈、七鳃鳗的5SrDNA基因序列进行同源性比较后发现,5种鲽形目鱼类5S rDNA基因序列同源性高达98.3%,系统发生分析结果显示5种鲽形目鱼类聚为一支;各序列中GC含量均显著高于AT含量。Using fluorescence in situ hybridization （FISH）, 5S rDNA gene was mapped on chromosomes of half-smooth tongue-sole（Cynoglossus semilaevis）and olive flounder（Paralichthys olivaceus）for the first time. The results showed that 5S rDNA has two hybridization signal loci in a pair of homologous chromosomes of male and female half-smooth tongue-sole, respectively; 5S rDNA has two and three hy- bridization signal loci in a pair of homologous chromosomes of diploid and triploid olive flounder, respec- tively, referring to the clear and specific hybridization signals. FISH mapping of 5S rDNA genes on the chromosomes of diploid half-smooth tongue-sole and triploid olive flounder provides a feasible method for ploidy and chromosome identification of half-smooth tongue-sole and olive flounder. In addition, the coding region sequences of 5S rDNA gene of turbot （Scophthalmus maximus） and half-smooth tongue-sole were amplified using same primers designed for olive flounder 5 S rDNA gene, and the phylogenetic analysis of the 5S rDNA genes in four species of flatfishes, including plaice（Pleuronectes platessa）, senegalese sole （Solea senegalensis）, largemouth bass（Micropterus salmoides） and arctic lam- prey（Lampetrajaponica） showed that the 5S rDNA gene of five species of flatfishes shared high homology （98.3%） and gathered into a branch. The GC content was significantly higher than the AT content in con- servative sequence of 5 S rDNA coding region of these five species of flatfishes.

关 键 词：牙鲆 半滑舌鳎 5S RDNA基因 荧光原位杂交 鲽形目 系统发生 

分 类 号：Q342[生物学—遗传学] S917.4[农业科学—水产科学]