皱纹盘鲍高温胁迫响应的分子机制研究

Pacific abalone (Haliotis discus hannai Ino) aquaculture is a thriving and prosperous industry in China. In recent years, the industry has flourished in Fujian, South China. However,summer mass mortality probably caused by high temerature stress impeded the development of Pacific abalone aquaculture industry. Although selective breeding for improving resistence to heat stress based on estimated breeding value (EBV) in cultured Pacific abalone stocks was carried out, it's important to investigate the molecular mechenism of resistence to heat shock stress in Pacific ablone for the purpose of providing guidelines for selective breeding of this trait. Based on resistent and susceptive F2 families as experimental materials， the project applied transcriptome profiling analysis to obtain candidated genes in terms of heat stress of this speices. In addition, the nucleotide sequence polymorphisms (SNPs) in candidated genes were projected to explore their association with susceptibility/resistance to heat stress. The associated SNP markers were then projected to be confirmed in expanded Pacific abalone stock. Further, the associated genes obtained from the protocol of the study were investigated for further functional analysis by bioinfomatics. The study aimed to elucidate preliminarily the molecular mechanism of resistence to heat stress in Pacific abalone. The application could be helpful in future selection of Pacific abalone with enhanced resistance to heat stress.

皱纹盘鲍是我国重要的海水养殖贝类，近年来福建等南方海区已成为主养区，但夏季大规模死亡问题仍困扰着产业发展。初步研究表明，高温胁迫可能是引起鲍夏季大规模死亡的原因之一。在开展皱纹盘鲍耐高温选择和相关分子生物学研究的基础上，本申请项目拟开展皱纹盘鲍高温胁迫响应的分子机制研究，不仅可为标记辅助选育提供依据，而且具有重要产业意义。本项目拟以皱纹盘鲍高温抗性及敏感家系F2为材料，利用转录组学技术获得高温抗性候选基因，并研究基因SNP位点及与高温抗性性状的相关性，将筛选出的对高温抗性有重要影响的功能分子标记在扩大群体中进行验证，并进一步对筛选出的关键基因开展功能分析，初步解析鲍高温抗性的分子机制。

本研究针对高温胁迫这一环境因子，分别采用实验室模拟方法系统研究了高温短期胁迫（acute stress）和长期胁迫（chronic stress）下皱纹盘鲍心率、血细胞吞噬力、活性氧水平等的生理响应，首次揭示皱纹盘鲍南北养殖群体高温胁迫下阿伦尼乌斯拐点温度（ABT）指标显著差异；采用现场调查等方法研究了皱纹盘鲍养殖群体度夏过程中的能量及免疫指标变化，指出养殖度夏过程中能量消耗及免疫指标的紊乱可能是导致度夏死亡主要原因。同时，对高温耐性和高温敏感的两个皱纹盘鲍选育群体进行了转录组测序和不同胁迫处理的表达谱测序，转录组测序组装、注释获得一批差异表达基因和SNP位点；并进一步对部分基因如丝氨酸蛋白酶抑制剂（Spi）基因、半胱氨酸蛋白酶抑制剂（Cpi）基因等在不同温度梯度下的表达模式进行功能分析和验证。初步揭示皱纹盘鲍对高温胁迫的生理响应及其分子机制，为将来的高温胁迫响应相关功能基因的确定和分子标记育种提供基础信息。