马氏珠母贝Rab7基因的克隆及其表达特征分析

Cloning and expression character analysis of Rab7 in Dunker Pinctada martensii

关键词:  马氏珠母贝  Rab  克隆  表达特征

Key words:  Pinctada martensii  Rab  Cloning  Expression character

摘要:

Rab 家族基因在囊泡的形成、转运、黏附、锚定和融合等各个阶段发挥重要作用。在已有的马氏珠母贝Rab cDNA片段的基础上，采用RACE方法克隆了该基因的全长。cDNA长度2 519 bp，编码区长618 bp，编码206个氨基酸。编码的蛋白质序列分析表明，该基因具有Rab家族的全部保守结构，与人类等其他生物的Rab7亚家族的同源性最高。RT-PCR结果显示，该基因在马氏珠母贝的鳃、足和胃组织中没有扩增产物，在卵、感染和未感染凿贝才女虫Polydora ciliata的马氏珠母贝的肝脏和血液中均检测到了与预期大小相符的扩增产物，存在组织差异性表达。

Abstract:

Rab gene family plays an important role for endosome in formation, transportation, anchoring and fusion of/with phagosome/lysosome.Based on the existing Rab cDNA fragment of Pinctada martensii,the total open reading frame was cloned by using RACE method.The total cDNA consists of 2519 bp,including a 618 bp coding sequence region.Analysis of deduced amino acid sequences showed that all conserved motifs and regions can be found among these 206 amino acids.Furthermore,it was suggested that this Rab gene was a Rab7 homology because its amino acids constitution was more similar to Rab7 of human beings and other organisms, than to any other Rab subfamilies. Rab7 transcripts could be detected at expected levels respectively in liver and blood of P.martensii infected or not infected with Polydora ciliate,and in mature eggs. However, nothing was found in gill,tropoda or stomach. These results suggested that Rab7 was a tissue-specific expressing gene and may be involved in special procedures.