热应激条件下SD大鼠生理生化指标变化分析及转录组水平差异表达基因筛选

发布时间：2018-04-19 06:37

本文选题：SD大鼠 + 热应激　；参考：《延边大学》2016年硕士论文

【摘要】：热应激不仅严重的威胁人类的生存,而且也严重制约受到热应激影响区域的畜牧业,尤其是奶业的发展。以热应激反应特征指标变化规律为出发点,挖掘热应激反应关联基因,深入探求动物机体热应激调节机制,并及时制定适合实际生产的行之有效的抗热应激管理策略和选种策略,对减轻动物热应激损伤、减少热应激造成的经济损失意义深远。因直接以奶牛为研究对象存在试验条件不可控、个体遗传背景差异大及成本高等缺点,本研究目的在于以SD大鼠为热应激反应模式动物,获得在可控的热应激条件下,热应激反应相关生理、生化指标及转录组水平基因差异表达的变化规律,筛选热应激敏感生化指标、敏感基因,获得参与热应激调节的重要生理、应激应答通路,探索热应激条件下机体的调节机制,为奶牛热应激相关研究奠定基础。本研究选用28只体重约180-210g雌性8周龄SD大鼠作为研究对象,随机分配到热应激组(HS组)(42℃、Relative humidity (RH)50%)及对照组(NC组)(25℃、RH50%)。对大鼠进行不同时间长度的热应激处理(HS30min.HS60min、 HS120min),分别检测大鼠血液、肝脏、肾上腺、腿肌等组织相关生化指标含量变化；选取热应激组HS120min处理及NC组SD大鼠的血液、肝脏和肾上腺组织进行转录组测序筛选差异表达基因。研究结果表明：1)环境温度为42℃、RH50%条件下,SD大鼠出现严重热应激,但无致死现象发生。42℃条件下分别HS30min、HS60min及HS120min时,大鼠体温由37.13℃度极显著上升至39.70℃、39.63℃及40.48℃,随后,体温呈持续高温状态；2) 42℃、RH50%的热应激情况下,应激HS120min时腿肌组织皮质酮(CORT)含量极显著高于NC组、HS30min组及HS60min组,肾上腺组织CORT含量显著高于NC组,而肺脏、心脏、肾脏、胃脏四个组织中CORT含量随应激时间延长呈现极显著下降趋势；随着热应激时间延长,腿肌组织多巴胺(DA)含量逐渐上升,至HS120min时DA含量极显著高于NC组水平。对HS120min时血液和腿肌组织生化指标热敏感性分析发现,GH (Growth hormone)是血液中对热刺激最为敏感的生化指标,CORT是腿肌组织中最为敏感的热应激生化指标。3)分别筛选到血液、肝脏及肾上腺组织差异表达基因98、3551和4484个,针对三个组织差异表达基因进行GO和通路分析结果显示,主要富集在细胞代谢、DNA和蛋白损伤修复及应激应答等功能,富集的通路主要为昼夜节律变化、固醇类激素合成通路、MAPK信号通路和PPAR信号通路及抗原加工呈递通路。本研究获得的热敏感生化指标以及热应激条件下组织差异表达基因等结果,揭示了热应激条件下,体温升高为大鼠最为直观的生理表现,为维持稳态,HPA轴被激活,相关激素和蛋白类生化指标含量发生变化,究其原因归结于热刺激诱导大鼠体内相关温度应激应答、蛋白损伤修复、激素合成等通路相互作用,共同减轻热应激损伤的生命机制。本研究将为畜禽热应激反应评定、热应激调节机制研究,乃至培育抗热应激品种提供基础数据。
[Abstract]:Heat stress is not only a serious threat to human survival, but also seriously restricted by heat stress in the affected area of animal husbandry, especially the development of the dairy industry. The variation of the heat stress response characteristics as the starting point, mining the heat stress response genes, explore the animal body heat stress regulation mechanism, and make suitable for the actual production the effective stress management strategy and selection strategy, to reduce the damage caused by animal heat stress, heat stress reduced the economic loss of far-reaching significance. Due directly to the cows as the research object of test conditions is not controllable, individual differences in genetic background and high cost, the purpose of this study is to SD rats as the animal model of heat stress response in the condition of heat stress, controllable, physiological response to heat stress, the law of change of differential expression of biochemical and transcriptional level of genes, screening of heat Sensitive biochemical indexes, stress sensitive gene, get involved in the physiological regulation of heat stress, stress response pathway, to explore the regulation mechanism of heat stress in the body, and lay the foundation for the research of dairy cows in heat stress. This study selected 28 body weight 180-210g female 8 week old SD rats as the research object, randomly assigned to heat stress group (HS group) (42 C, Relative humidity (RH) 50%) and control group (NC group) (at 25 RH50%). The rats were subjected to heat stress of different lengths (HS30min.HS60min, HS120min), were detected in rat blood, liver, adrenal gland, leg muscle related biochemical changes content index; selection of heat stress group HS120min and group NC SD rat blood, liver and adrenal tissue transcriptome sequencing screening differentially expressed genes. The results show that: 1) the environment temperature is 42 DEG C, RH50%, SD in rats of severe heat stress Shock, but no death occurred at.42 DEG C respectively HS30min, HS60min and HS120min, the body temperature of rats by 37.13 DEG C significantly increased to 39.70 degrees, 39.63 degrees and 40.48 degrees, then the temperature was sustained high temperature state; 2) at 42 RH50% heat stress, stress HS120min leg muscle tissue corticosterone (CORT) was significantly higher than that in NC group, HS30min group and HS60min group, CORT in adrenal gland was significantly higher than that of NC group, and the lung, heart, kidney, stomach CORT in four tissues showed significantly decreased with stress time prolonged; with the heat stress time prolonged, leg muscle tissue (dopamine DA) content gradually increased to HS120min, when the DA content was significantly higher than NC group. The level of HS120min tissue blood biochemical index and leg muscle sensitivity analysis showed that the GH (Growth hormone) in the blood of the most sensitive biochemical indexes of heat stimulation, CORT leg muscle group Thermal stress is the most sensitive biochemical indexes of.3) were screened in the fabric of blood, 983551 genes and 4484 differentially expressed in liver and adrenal tissues, GO gene and pathway analysis showed that the expression differences between the three organizations, mainly enriched in cell metabolism, DNA and protein damage repair and stress response function, enrichment pathway mainly for the circadian rhythm of steroid hormone synthesis pathway, MAPK signaling pathway and PPAR signaling pathway and antigen processing and presentation pathway. Gene expression and tissue biochemical indexes and the difference between the results under heat stress sensitive obtained in this study, reveals the condition of heat stress, temperature is the most intuitive for the physiological performance of rats in order to maintain steady, HPA axis is activated, hormones and protein biochemical changes occur, the reason is due to the heat induced in temperature stress response of rat eggs This study will provide basic data for evaluating heat stress response, regulating mechanisms of heat stress, and even cultivating heat stress resistant varieties.

【学位授予单位】：延边大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S852.3

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