中文摘要：

为探明EXO70基因在白菜和甘蓝基因组中的倍增,从BRAD数据库中分别搜索并鉴定出39和45种不同的EXO70基因.分析发现,同种EXO70及其编码基因在白菜和甘蓝中极度保守,不同类型EXO70的氨基酸组成存在差异,pfam03081是每个EXO70蛋白所共有;不同EXO70基因的外显子数目差异明显,尤以EXO70A的外显子数目最多;Bo EXO70在进化过程中发生了较BrE XO70程度更高的DNA丢失情况;白菜和甘蓝EXO70基因总的密码子偏性近乎相同,而不同类EXO70基因之间的密码子使用却出现程度不同的差异.得出推论,尽管EXO70基因在两物种中拥有近乎相同的倍增模式,它在甘蓝中的倍增程度高于白菜;同种类型的EXO70基因在白菜和甘蓝中高度保守,pfam03081是决定EXO70蛋白功能的关键因素;EXO70基因在两个物种内的倍增表现出趋异的进化.

英文摘要：

To understand EXO70 gene duplication in Brassica rapa and B. oleracea genomes, we identified and analyzed 39 Br EXO70 and 45 Bo EXO70 genes. EXO70 s from B. rapa show the same pattern of high interspecies conservation as those from B. oleracea. The number of exons differs among EXO70 genes, with the greatest number observed in EXO70 A. Although each encoded EXO70 contains a highly conserved pfam03081 domain, the domains differ from one another in amino acid composition. The gene duplication mechanism of BoE XO70 is more complex than that of Br EXO70. Although few differences in synonymous codon preference exist between Bo EXO70 and Br EXO70, obvious differences in codon preference are present among different EXO70 types. We conclude that EXO70 has been duplicated multiple times during the evolution of both B. rapa and B. oleracea. More duplications have occurred in B. oleracea than in B. rapa, even though the same modes of gene duplication are found in both Bo EXO70 and BrE XO70. In addition, high conservation is exhibited by the same types of EXO70 genes in both B. oleracea and B. rapa. We also propose that the pfam03081 domain plays an essential role in EXO70 functional determination. Finally, EXO70 evolutionary divergence is evident in both B. rapa and B. oleracea.