中华蜜蜂HSC70-4基因表达特性的研究

Expression characteristcs of HSC70-4 gene in Apis cerana cerana (Hymenoptera:Apidae)

组成型热休克蛋白70-4(heat shock protein 70 cognate 4,HSC70-4)是HSP70家族的重要成员,对蛋白质的正确折叠与转运有着重要意义。本研究以中华蜜蜂转录组数据中获得的HSC70-4基因序列为基础,通过对中华蜜蜂不同发育阶段、不同组织以及不同低温胁迫下的HSC70-4 m RNA表达量进行测定,以期为揭示该基因在中华蜜蜂生长发育和耐寒抗冻过程中的生理功能提供理论依据。结果显示,中华蜜蜂HSC70-4基因包含1923 bp的开放阅读框,编码641个氨基酸,蛋白分子量为70.4 k Da。中华蜜蜂HSC70-4氨基酸序列中包含3个HSP70家族的标签序列,其N端含有HSC70家族的GGXP四肽结构标志,C端包含EEVD结构。与膜翅目其它昆虫的氨基酸序列一致性在94%以上,具有较高的保守性。中华蜜蜂HSC70-4在成虫期的表达量显著高于幼虫期和蛹期(P<0.01),从幼虫期至10日龄成虫期呈逐渐上升趋势,但在15日龄至30日龄间呈现波动起伏。HSC70-4在中华蜜蜂不同组织中的表达存在显著差异(P<0.01),且在胸部高度表达,在足中中度表达,在其余组织中低度表达。中华蜜蜂HSC70-4的表达受低温胁迫的诱导,在低温胁迫2 h时其表达量最低,4 h时表达量最高。本研究结果表明中华蜜蜂HSC70-4在中华蜜蜂的生长发育过程中应对低温胁迫时发挥生理功能。

Heat shock protein 70 cognate 4 is an important member of the family of HSP70 and play an important role in the correct folding and transmission of proteins. In order to explore the physiological function of HSCI0-4 gene in response to different development stages and low temperature stress of Apis cerana cerana. Based on the successful transcriptome sequencing in A. c. cerana, we analyzed the nucleotide and amino acid sequence of HSC10-4 and used RT-qPCR to analyze the expression of HSC10-4 in different development stages, tissues and response to different low temperature stress. Sequenceanalysis results showed HSC70-4 of A. c. cerana include a 1923 bp open reading frame, encoding a polypeptide of 641 amino acids with an estimated molecular mass of 70. 4 kDa. HSC10-4 contained 3 sequence labels of the HsplO gene family. Sign sequence of GGXP and EEVD were contained in N-terminal and C- terminal, respectively. The amino acids sequence comparison showed that the HSC70-4 had a 94% of similarity with other Hymenoptera, indicating the high level of gene conservation. Expression of HSC10-4 in adult was higher than larval and pupal （P 〈0. 01） . It increased from larval to adulO and fluctuated from adul5 to adu30. The expression levels of HSC70-4 were significantly different among different tissues （P 〈0. 01） , with the highest expression level in thorax, the higher expression level in leg and the lowest levels in other tissues. The expression of HSCI0-4 was induced by low temperature stress, the minimum and maximum of expression of HSC70-4 mRNA were low temperature treatments for 2 h and 4 h , respectively. This study displayed HSC70-4 gene involve in the growth and development of A. c. cerana and plays significant psychological functions in response to low temperature stress.