冬枣COBRA基因家族全基因组鉴定及表达分析

Genome-wide Identification and Expression Analysis of COBRA Gene Family in Ziziphus jujuba

COBRA作为一类GPI锚定蛋白,主要作用于细胞伸长与纤维素沉积。本研究在"冬枣"全基因组中成功地鉴定到10个冬枣COBRA相似基因(ZjCOBL),并对该基因家族成员进行生物信息学分析,还研究了各成员在‘冬枣’7个不同组织中的表达模式。所有潜在的COBRA相似蛋白都具有CCVS保守结构域,其中8个相似蛋白具有N端信号肽序列,big-PI程序预测出7个蛋白为潜在的GPI锚定蛋白。根据基因结构和系统演化分析等依据,冬枣中的COBRA相似蛋白可以分为两个亚家族(SFs),其中SFⅠ亚家族氨基酸相似性为43.3%到79.9%,SFⅡ亚家族为58.3%到67.9%。10个ZjCOBL基因分别位于枣树12条染色体中的5条染色体和一段scaffold上。Real-time RT-PCR试验表明,所有ZjCOBL基因在冬枣各个器官和不同生长时期均有表达。其中,ZjCOBL7与番茄上的Sl COBRA-like为直系同源基因,具有相似的表达模式,推测ZjCOBL7可能与枣果实的质地和成熟软化相关。

COBRA,a kind of GPI anchored protein,is mainly involved in cell expansion and cellulose deposition.We successfully identified 10 COBRA-like genes in‘Dongzao’genome（ZjCOBL）.These genes were analyzed by bioinformatics method and their expression patterns in seven tissues were further investigated.All potential COBRA-like proteins had a conserved CCVS domain,among which eight had N-terminal signal peptide sequence.Seven of the members were predicted as potential GPI anchored proteins using the big-PI program.Based on gene structure and phylogeny analysis,the members could be divided into two subfamilies（SFs）.Among the SFⅠ,the identity ranged from 43.3% to 79.9% while it ranged from 58.3% to 67.9% in the SF Ⅱ.10 ZjCOBL genes we’re located on 5 chromosomes and a scaffold sequence.Real-time RT-PCR showed that all genes expressed in different tissues and developing stages.ZjCOBL7 and SlCOBRA-like are orthologs with similar expression pattern in different tissues,indicating that ZjCOBL7 might play important role in the regulation of fruitdevelopment and ripening in Ziziphus jujuba.