摘要
作者根据子孢子微线基因(Etmic-2)的 cDNA 序列,利用计算机设计出一对引物,从孢子化7h 卵囊中用 RT-PCR 技术扩增出1个片段(mic2～7h).把这个片段克隆到 pGEM-T-Easy Vector 中后,我们得到一个阳性克隆 pmic2～7h.酶切分析证明 pmic2～7h 含有 mic2～7h,并且外源片段以反方向插入 T 载体中.核苷酸序列测定结果表明 mic2～7h 比 Etmic-2基因至少长111bp.但这多出的111bp 并没有造成基因读框错位,也没有造成基因读框终止.这111bp 由2部分组成,一部分长42bp,另一部分长69bp.虽然这二个片段的3′端均有典型的真核生物 mRNA 内含子剪切信号,但5′端却没有内含子的剪切信号点.这说明多出来的111bp不是内含子序列,mic2～7h 基因也不是 Etmic-2基因的前体,而可能是 EtMIC-2的一种蛋白异形体基因.
According to the Etmic-2 cDNA sequence published by Tomley,we designed a pair of primers designed by using computer software.A 1.2 kb cDNA encoding sequence of Etmic-2 from sporulating～7h oocysts,named mic2～7h,was amplified by RT-PCR (taking cDNA as template).This PCR product was cloned into pGEM-T-Easy vector by T-A ligation,and identified with restriction endonuelease analysis,and sequenced by auto- matic DNA sequencer.Comparing sequence of mic2～7 h with that of Etmic-2 shows mic2 ～7 h has additional 42 bp and 69 bp nucleotide.3'of two short sequences is a 3'site of typical eukaryotic intron,while 5'is not 5'splice site.This implies that mic2～7 h is not the pre-mRNA of Etmic-2,and may be a cDNA of EtMIC-2 protein isoform.
出处
《中国农业大学学报》
CAS
CSCD
北大核心
1998年第S2期10-13,共4页
Journal of China Agricultural University
