斑节对虾α-淀粉酶基因的克隆及其表达分析

CLONING AND EXPRESSION ANALYSIS OF ALPHA AMYLASE CDNA OF PENAEUS MONODON

  • 摘要: 为了研究斑节对虾α-淀粉酶基因的结构和生物学功能, 根据原实验室构建的斑节对虾(Penaeus monodon) cDNA文库得到的EST序列, 利用RACE技术获得了斑节对虾α-淀粉酶基因(PmAmy)的cDNA全长序列。该基因序列全长2465 bp, 包括2175 bp的开放阅读框, 编码724个氨基酸, 分子总量为78.9 kD, 理论等电点为4.66。PmAmy包含一个α-淀粉酶家族保守的A结构域(Thr34-Ser410)和一个C结构域(Glu420-Ala496)。PmAmy氨基酸序列与其他物种的相似性为47%—99%, 利用PmAmy构建的进化树显示斑节对虾和凡纳滨对虾(Litopenaeus vannamei)的亲缘关系最近。基因表达结果显示PmAmy在肝胰腺组织中的表达量显著高于其他组织(P<0.05)。斑节对虾PmAmy基因在卵巢发育的过程中均有表达, 表达量有所变化, 虽然没有发现显著性的差异(P=0.09)。斑节对虾PmAmy在整个生长阶段的检测中都有表达, 其中幼体发育过程中存在显著性差异, 糠虾时期PmAmy表达量显著高于无节幼体、溞状幼体和仔虾时期(P<0.05)。以上实验结果初步说明了PmAmy可能与斑节对虾的幼体发育相关。

     

    Abstract: In order to study the structure and biological function of the alpha-amylase gene in Penaeus monodon, the full-length cDNA sequence of α-Amylase from Penaeus monodon (PmAmy) was obtained by high throughput transcriptome sequencing and RACE. The PmAmy cDNA included an open reading frame of 2175 bp encoding a polypeptide of 724 amino acids, and the predicted molecular mass and isoelectric point were 78.9 kD and 4.66, respectively. The PmAmy contained a conservative A domain (Thr34-Ser410) and a C domain (Glu420-Ala496) of alpha amylase family. Homology analysis revealed that the PmAmy shared 47%—99% identity to other known amylase sequences, and the phylogenetic tree showed that the PmAmy was closely related to Litopenaeus vannamei. The expression levels of PmAmy in hepatopancreas were significantly higher than those of the other tissues (P<0.05). ThePmAmy expression was found in five ovarian development stages. The expression level in yolky stage (stageⅣ) was the highest among the five stages, and was the lowest in ovogonium stage (stageⅠ). The expression levels of PmAmy showed no significantly difference in ovary development stages. Expression of PmAmy was detected in all tested growth stages, and the expression level in mysis was significantly higher than that in nauplius, zoea and post larval (P<0.05). These results suggested thatPmAmy might be associated with larval development in P. monodon.

     

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