【摘要】 根据Ty1-copia类逆转座子逆转录酶的保守区设计简并引物,通过PCR扩增,从黄瓜属野生种酸黄瓜(Cucumis hystrix Chakr.)和栽培黄瓜(Cucumis sativus L.)中均扩增出260bp左右的目标条带。扩增产物经纯化后克隆于pGEM-TEasy质粒载体,选择阳性克隆,再经菌落PCR鉴定,然后进行测序及序列分析,获得了21条来源于酸黄瓜和栽培黄瓜的逆转录酶序列,通过核苷酸聚类分为5个家族。这些核苷酸序列具有较高的异质性,主要表现为缺失突变,序列长度变化范围为255~272bp,同源性范围为27.0%~98.1%。翻译成氨基酸后,有4条序列出现终止密码子突变,6条序列表现出移框突变。将这些逆转录酶的氨基酸序列与已登录的不同物种同一类型逆转录酶的氨基酸序列进行聚类分析,表明它们可能有共同的起源。更多还原

【Abstract】 Using degenerate oligoncleotide primers corresponding to conserved domains of the Ty1-copia retrantranspon reverse transcriptase,a fragment of 260 bp was amplified by PCR from Cucumis hystrix and C.sativus.The amplicons were cloned into pGEM-T Easy vector after purification,positive clones selected and identified by colony PCR,then sequenced and analyzed.Twenty-one different sequences of reverse transcriptase from Cucumis hystrix and C.sativus’Beijing Jietou’ were obtained,and five families were distinguished after cluster and alignment analyses of their nucleotide sequences.These sequences showed high heterogeneity mainly characterized by deletion mutation.The length of the nucleotide sequences varied from 255 to 272 bp,and homology ranged from 27.0% to 98.1%.When translated into amino acids,four sequences presented stop codon mutation,and six sequences presented frameshift mutation.The amino cluster and alignment analyses of these sequences with other reverse transcriptase sequences from other accessions showed that they may have the same origin.更多还原