旋毛虫新生幼虫脱氧核糖核酸酶Ⅱ基因家族的筛选和分析

Screening and Analysis of a Newborn Larvae DNase Ⅱ Gene Family of Trichinella spiralis

利用旋毛虫新生幼虫期特异性基因N5cDNA作为探针,对旋毛虫新生幼虫cDNA文库进行筛选,并将阳性克隆全部送测序公司测序。对测序结果进行序列分析后,根据信号肽不同分为15种基因。NCBI BLAST检索表明,其中有13种基因均为旋毛虫未知基因序列,并且氨基酸序列最前面均包含有1个信号肽,属于分泌性蛋白。InterProScan检索表明,15种氨基酸序列均编码脱氧核糖核酸酶Ⅱ（DNaseⅡ）,均含有DNaseⅡ的保守序列。通过互联网将编码蛋白序列输入CLUSTAL W数据库,检索结果表明,这些编码的脱氧核糖核酸酶Ⅱ蛋白质同源性高达85%-98%。

cDNA library of Trichinella spiralis newborn larvae （NBL） was screened with specific probe of N5cDNA and positive clones were sequenced. Sequence analysis revealed 15 genes according to different signal peptides. Thirteen of them were not recorded in NCBI BLAST and each contained a signal peptide upstream of encoded peptides which were believed to be secretory proteins. InterProScan searching indicated that all of these 15 genes encoded DNase Ⅱ and contained consensus sequence of DNase Ⅱ . We input amino acid sequences into CLUSTAL W database by www. The results indicated that these genes encoding DNase Ⅱ proteins showed homology from 85 % to 98 %.