小立碗藓扩展蛋白基因家族的鉴定与生物信息学分析

Identification and bioinformatic analysis of Expansin gene family in Physcomitrella patens

关键词:  小立碗藓, 扩展蛋白, 基因家族, 生物信息学

Key words:  Physcomitrella patens, Expansin, gene family, bioinformatics

摘要:

扩展蛋白(Expansins, EXP)是一类基因家族,几乎参与了植物发育的全过程,从种子萌发到果实成熟都有扩展蛋白的参与。该研究利用生物信息学的方法对小立碗藓(Physcomitrella patens)Expansin基因家族成员进行鉴定,分析了其基因结构、染色体定位以及系统发生关系。结果表明:小立碗藓基因组中含有Expansin A(EXPA)32个、Expansin-like A(EXLA)6个,并未发现Expansin-like B(EXLB)及Expansin B(EXPB)。扩展蛋白氨基酸序列长度在228～290 aa之间,编码蛋白质具有两个保守的结构域Pollen_allerg_1和DPBB_1。蛋白质亚细胞定位预测结果表明:运用CELLO在线工具预测发现小立碗藓中约4/5的EXP家族基因定位于细胞外; 而Euk-mPLoc预测结果则显示小立碗藓EXP基因家族成员全定位于细胞外。基因结构分析表明,小立碗藓中约68% Expansin 基因有含有1～3个内含子。以上结果可为深入研究小立碗藓扩展蛋白基因的分子进化与生物学功能奠定基础。

Abstract:

Expansins(EXP)is a family of genes that are involved in the whole process of plant development. From seed germination to fruit ripening, there are Expansins involved. Bioinformatics methods were used to identify the members of the Expansin gene family of Physcomitrella patens, and their gene structures, chromosomal locations and phylogenetic relationships were analyzed. The results were as follows: Genome of the P. patens contains 32 Expansin A(EXPA)and 6 Expansin-like A(EXLA), but Expansin-like B(EXLB)and Expansin B(EXPB)were not found. The Expansin amino acid sequence is between 228-290 aa in size, and the encoded protein has two conserved domains, Pollen_allerg_1 and DPBB_1. The results of protein subcellular localization prediction showed that about 4/5 of the EXP family genes in the P. patens were located outside the cell using the CELLO online tool; while the Euk-mPLoc prediction showed that the EXP gene family member was fully localized in extracellular. Gene structure analysis showed that about 68% of the Expansin gene in P. patens contains 1-3 introns. This study analyzed the basic information of the P. patens extended protein gene family, which lays a foundation for further study of the molecular evolution and biological functions of its extended protein genes.