【摘要】 从四倍体鱼脑垂体中提取总RNA,用RT-PCR方法扩增并克隆了四倍体鱼GTH-α亚基4种不同的cD-NA,分别命名为GTH-α1、GTH-α2、GTH-α3和GTH-α4.其中,GTH-α1和GTH-α2的cDNA都由363个核苷酸组成,编码117个氨基酸;而GTH-α3和GTH-α4都由366个核苷酸组成,编码118个氨基酸.分析表明,四倍体鱼4种不同的GTH-α亚基之间的核苷酸和氨基酸的同源性非常高,均在96%以上;四倍体鱼和原始亲本红鲫和鲤鱼GTH-α亚基氨基酸序列之间的同源性也非常高,如四倍体鱼GTH-α1和原始母本红鲫GTH-α1氨基酸的同源性为99.2%,四倍体鱼GTH-α3和原始父本鲤鱼GTH-α1氨基酸的同源性达到了100%.更多还原

【Abstract】 Total RNA is isolated from the tetraploid fish pituitary.The first strand cDNA is synthesized using oligo(dT)18 as a primer,the total RNA as a template,and AMV reverse transcriptase.Four types of cDNA encoding the α subunit of gonadotropin(GTH) are amplified and cloned by polymerase chain reactin(PCR) for the first strand cDNA of the tetraploid fishes.The tetraploid fishes GTH-α subunit cDNAs are named as α1,α2,α3,and α4.The nucleotide sequences of GTH-α1 and α2 cDNA are 363 bp in length,encoding 117 amino acids,and those of GTH-α3 and α4 are 366 bp in length,encoding 118 amino acids.These four types of GTH α subunits show higher homology(more than 96.0%) including the nucleotide and the amino acids.Moreover,high homology is observed by amino acids sequence alignment and identity comparison of the tetraploid fishes GTH-α subunit cDNAs with that of their original parents.For example,the homology of the amino acids sequences between the tetraploid fishes GTH-α1 and their maternal red crucian carp GTH-α1 is 99.2%,and that of the amino acids sequences between the tetraploid fishes GTH-α3 and their paternal common carp GTH-α1 is 100%.更多还原