缢蛏急性高温胁迫应答主要候选基因的表达特征分析

Analysis of Expression Characteristics of Related Genes in Response to Acute Thermal Stress in the Razor Clam Sinonovacula constricta

中文关键词: 缢蛏  高温胁迫  qRT-PCR  基因表达

英文关键词: Sinonovacula constricta  Thermal stress  qRT-PCR  Gene expression

中文摘要:

      缢蛏(Sinonovacula constricta)为广温性贝类，自身存在特殊的防御机制以适应外界温度胁迫。为研究高温胁迫对缢蛏热应激相关基因表达的影响，利用实时荧光定量PCR (qRT-PCR)技术对转录组中筛选的3类11个高温应答候选基因，即分子伴侣类基因(HSP70、HSF1、GRP94、BAG3、PDIA6和CALR)、代谢与免疫应答类基因(MDH、CTL和CTSL)和细胞凋亡类基因(Caspase-3和p53)，在不同温度(30℃、32℃和34℃)胁迫下，在鳃和肝胰腺中的表达特征进行了分析。结果显示，分子伴侣类基因受温度影响最为显著，胁迫4 h时表达量开始显著升高，与温度呈正相关，且鳃较肝胰腺更早做出响应；代谢与免疫应答类基因和细胞凋亡类基因在鳃、肝胰腺中的表达均随胁迫时间延长呈先升高后下降的趋势；免疫应答类基因在肝胰腺中的响应更显著。综上所述，高温胁迫下缢蛏维持基本生命稳态与这3类基因的调控密切相关。本研究为进一步探索贝类高温响应分子机制奠定理论基础，也为耐高温缢蛏新品种分子标记辅助选育提供候选基因。

英文摘要:

      The razor clam, Sinonovacula constricta, as a eurythermic bivalve, might have special adaptive mechanisms for defense against environmental stress because of its specialized lifestyle and limited mobility. To understand the expression characteristics of genes involved in different metabolic processes, quantitative reverse transcription PCR technology was used to analyze the expression levels of three types of temperature response candidate genes (molecular chaperone genes, metabolic and immune related genes, and apoptosis genes) based on a transcriptomic analysis in the gills and hepatopancreas of S. constricta under different acute high temperature conditions (30℃, 32℃ and 34℃). The results showed that the expression of molecular chaperone genes was significantly upregulated at 4 h under thermal stress and was positively correlated with temperature. Meanwhile, gills responded earlier than the hepatopancreas. The mRNA expression of metabolic and immune responses and apoptotic genes increased and then decreased in both tissues with the extension of stress time. In conclusion, the regulation of these genes played significant roles to maintain basic homeostasis in S. constricta under heat stress. The expression of immune response genes was more significant in the hepatopancreas. This study provides a theoretical basis for further exploring the molecular mechanisms of high temperature responses of S. constricta and provides candidate genes for molecular marker-assisted breeding in this species under thermal stress.