东方鲀生长激素基因内含子2的克隆与多态性分析  

Cloning and polymorphism analysis of intron 2 of the GH gene in Takifugu

作　　者：黄军[1] 严美姣[1] 陈国宏[1] 许盛海[1] 鞠慧萍[1] 程金花[1] 吴云良[1] 

机构地区：[1]扬州大学动物科学与技术学院,扬州225009

出　　处：《遗传》2007年第11期1378-1384,共7页Hereditas（Beijing)

基　　金：扬州大学博士科研启动基金资助~~

摘　　要：以暗纹东方鲀(Takifugu obscurus)、红鳍东方鲀(Takifugu rubripes)、星点东方鲀(Takifuguniphobles)共82个个体为对象,运用PCR产物电泳检测、单链构向多态性(SSCP)技术和克隆测序技术检测到生长激素(Growth Hormone,GH)基因内含子2的长度和序列多态性。结果表明,3个群体中GH基因内含子2存在9种长度类型,分别为A、B、C、D、E、F、G、H、I,变异频率达到24.22%。对这9种序列进行比对分析,(1)发现9种长度类型A、G、T、C的平均百分比为17.15%、20.77%、37.38%、24.70%,其中G+C(45.47%)含量与A+T(54.53%)的含量差异不显著;(2)9种序列分别长351bp、327bp、319bp、303bp、295bp、291bp、287bp、283bp和271bp,引起长度变化的主要原因是短串联序列TCTG的重复(重复次数从20到40不等);(3)发现4个突变位点,其中3个转换位点为83(C→T),101(A→G)296(G→A),一处颠换位点103(C→A)。用UPGMA法构建分子系统树,发现DD与II首先聚为一类,然后依次与GG、AA聚为一大类,BB与CC,EE与HH分别聚为一类,最后再与FF聚为一大类,由此可见GH基因内含子2在品种间的差异远大于品种内差异。Size and nucleotide polymorphisms of intron 2 of the growth hormone （GH） gene was studied in 82 individuals from Takifugu obscurus, Takifugu rubripes and Takifugu niphobles with PAGE, SSCP and cloning. Results showed that there were nine length variants （A-I） in these fishes, ranging from 271 - 351 bp, with a frequency of variation of 24.22%. Sequence analysis of the 9 length variants showed the average percentages of the four bases （A, T, G and C） were 17.15 %, 20.77%, 37.38% and 24.70%, respectively, and the difference between GC content （45.47%） and AT content （54.53%） was not remarkable. Length variation was mainly due to the variable number of microsatellite TCTG repeats （N=20-40）. Further sequence comparison revealed 4 substitution sites： a （C→A） transversion at nucleotide 103 and 3 transitions 83（C→T）, 101（A→） and 296（G→A）, respectively. Phylogenetic analysis of these length variants placed DD and II into one group firsL which was subsequently joined by GG and AA, BB and CC, EE and HH were then clustered together, FF was joined last. Thus, intraspecific variations were much smaller than interspecific variations for the intron 2 of the GH gene.

关 键 词：东方鲀 生长激素基因 内含子 多态性 

分 类 号：Q953[生物学—动物学] Q78