【摘要】 采用RT-PCR(reverse transcription-polymerase chain reaction)和cDNA末端快速扩增(rapid amplification of cDNA ends,RACE)技术首次从秀丽白虾Exopalaemon modestus卵巢中克隆了PL10基因的cDNA全长序列。秀丽白虾的PL10基因(Em-PL10)cDNA全长2559 bp,开放阅读框(open reading frame,ORF)2154 bp,编码717个氨基酸。秀丽白虾PL10蛋白含有DEAD-box家族蛋白的8个保守结构域和GG重复序列,在N端具有5个RGG重复,与日本沼虾、中国明对虾、果蝇等相关蛋白的同源性分别为92%、81%和64%。亚细胞定位预测秀丽白虾PL10蛋白定位于细胞核中。系统进化分析显示秀丽白虾基于PL10基因的分子进化地位完全与形态学分类地位相吻合。半定量RT-PCR检测结果显示,Em-PL10 mRNA在各组织中均能表达,在卵巢中表达量最高,其次是精巢,而在胸神经节、鳃和肝胰腺中的表达量较少。更多还原

【Abstract】 The PL10 gene of white shrimp( Exopalaemon modestus) encodes an ATP-dependent RNA helicase which belonging to the DEAD box family. In this study,a full-length cDNA sequence of the PL10 gene was cloned from the ovaries of white shrimp by reverse transcription-polymerase chain reaction( RT-PCR) and rapid amplification of cDNA ends( RACE) methods. And the structure and speculated function of PL10 were analyzed. The full length of Em-PL10 was comprised of 2559 nucleotides with a 3’ untranslated region( UTR) of 318 bp,a 5’ UTR of 87 bp and an open reading frame( ORF) of 2154 bp,encoding 717 amino acids. The putative amino acid sequence shared eight conserved motifs of the DEAD-box family and GG doublet. And there were five arginine-glycine-glycine( RGG) repeats which might be functioned as RNA-binding in the N-terminal portion. Sequences comparison revealed that the deduced amino acid sequence of EmPL10 showed high similarity to the PL10 homologs of Macrobrachium nipponense( 92%),Fenneropenaeus chinensis( 81%)and Drosophila melanogaster( 64%). Subcellular localization analysis showed that the PL10 protein of E. modestus was located in nucleus. In addition,phylogenetic analysis based on amino acid sequences of PL10 suggested that E. modestus was closely related to M. nipponense. Furthermore,tissue expression of Em-PL10 was detected by semi-quantitation RT-PCR.The results showed that the expression of Em-PL10 could be detected in variant tissues,and the highest expression level was detected in ovaries followed by testes. The RT-PCR results also indicated that there was little expression of this gene in thoracic ganglions,gills and hepatopancreas.更多还原