水稻干尖线虫SPRYSEC基因的克隆及表达定位分析

Clone and expression analysis of a gene encoded scereted SPRY domain containing protein （SPRYSEC） in Aphelenchoides besseyi

根据水稻干尖线虫转录组测序结果,采用c DNA末端快速扩增技术（RACE法）从水稻干尖线虫中克隆到效应因子SPRY同源基因,并将其命名为Ab–SPRYSEC（NCBI登录号为KT188820）。该基因全长为2 089 bp,包含1个1 962 bp的开放阅读框（ORF）。预测蛋白编码653个氨基酸,相对分子质量为72 009,理论等电点为4.82,不稳定指数为41.5,属于不稳定性蛋白。保守区预测分析结果表明,该蛋白含有B302_SPRY和CTLH 2个保守结构域,属于SPRY超家族。多序列比对分析结果表明,该基因编码蛋白与马来丝虫的SPRY（XP_001891979.1）蛋白的相似度为43%。蛋白结构分析结果表明,β–折叠与无规则卷曲是Ab–SPRYSEC蛋白的主要结构元件。表达定位分析结果表明,Ab–SPRYSEC基因的表达位置在水稻干尖线虫食道腺附近。Ab–SPRYSEC基因作为水稻干尖线虫效应因子,在水稻干尖线虫侵染宿主中发挥了重要作用。

According to the results of transcriptome sequencing, one SPRY gene named Ab-SPRYSEC was cloned from Aphelenchoides besseyi using RACE method. The sequence of Ab-SPRYSEC was 2 089 bp including a 1 962 bp open reading frame （ORF）, which encoded a polypeptide of 653 amino acids. The predicted protein molecular weight was 72 009, with a theoretical isoelectric point 4.82. The predicted protein belongs to unstable protein with instability index of 41.5. The analysis from conserved domain showed that the protein belongs to the SPRY superfamily with two conserved domains which were B302_SPRY and CTLH; 43% of high similarity between A. besseyi SPRYSEC and Brugia malayi SPRY （XP_001891979.1） was founded from multiple sequence alignment. Results from protein structure analysis showed that 13-sheet and random coil were the main components; furthermore, results from in situ hybridization indicated that Ab-SPRYSEC gene was expressed in nematode dorsal esophageal gland. As an effector ofA. besseyi, the Ab-SPRYSEC gene might play important roles in the course of parasitism.