本文利用PCR技术，分别从柔嫩艾美耳球虫的第二代裂殖子和孢子化卵囊基因组DNA中扩增出微线蛋白EtMIC-2基因序列，并进行了克隆和核苷酸序列测定。核苷酸序列表明Etmic-2基因包含有二种cDNA序列，并含有3个内含子，每一个内含子都有真核生物内含子典型剪切共有序列(GT／AG)。与二种cDNA序列比较发现，Etmic-2基因的pre-mRNA可以通过内含子的3’端的不同剪切位点而产生不同的mRNA，生成至少两种蛋白异形体。本文从基因序列上解释了EtMIC-2蛋白的二种蛋白异形体产生过程。%Two fragment of Etmic-2 was cloned and sequenced by PCR using genomic DNA as template from sporulated oocysts and the second generation merozoite of Eimeria tenella．This sequence included three typical eukaryotic intron and two known cDNA sequence of Etmic-2.Analysis of genomic sequence and cDNAs from spolulating-7 h oocysts，sporozoite and the second generation merzoite implied that pre-mRNA of Etmic-2 at least generated two different proteins by alternative RNA sp licing．Abnormity of protein profile in SDS-PAGE，reaction with the same antibody，and therotical explanation from the genomic sequence strongly indicates that EtMIC-2 protein has at least two protein isoform．
展开▼
