Identification of heat shock protein gene expression in hair follicles as a novel indicator of heat stress in beef calves
Identification of heat shock protein gene expression in hair follicles as a novel indicator of heat stress in beef calves
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DOI：
10.1017/s1751731120000075
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发表时间：
2020-07-01
期刊：
影响因子：
3.6
通讯作者：
Lee, H. G.
中科院分区：
文献类型：
--
作者：
Kim, W. S.;Nejad, J. Ghassemi;Lee, H. G.
热休克蛋白（HSPs）由高度保存的应激蛋白组成，这些应激蛋白在应激反应中表达。为探讨热休克蛋白（HSP）基因是否可以作为热应激（HS）的指标，开展了两项研究。在研究1中，研究人员在2017年4月10日至8月9日的6天内，从3头雄性韩宇犊牛（年龄为172.2±7.20天）身上采集毛囊。这些天提供了不同的温湿度指数（THIs）。试验2将16头年龄为169.6 +/- 4.60日龄、体重为136.9 +/- 6.23 kg的韩宇公犊牛（每试验4头）饲养在环境控制箱中。完全随机设计，2 × 4因子排列，包括两个时期（热中性：TN； HS）和四个THI治疗组（阈值：THI = 68至70；轻度：THI = 74至76；中度THI = 81至83；重度：THI = 88至90）。不同组小牛在环境温度（22℃）下接受7天（TN），随后在与THI目标水平相对应的温度和湿度下接受21天（HS）。在TN和HS期间，每3天（1400h）测量每只个体的心率（HR）和直肠温度（RT），随后从每只个体的尾部收集毛囊。在研究1中，THI变化较大（P< 0.0001），说明外部环境对HS有不同程度的影响。HSP70和HSP90基因在高thi水平下的表达量高于低thi水平（P= 0.0120，P= 0.0002）。研究2的THI （P= 0.2638）、HR （P= 0.2181）和RT （P= 0.3846）在TN期各组间无差异，而HS期各组间差异分别为P< 0.0001、P< 0.0001和P< 0.0001。快速热应激（中度和重度）后，HSP70 （P= 0.0010，中度）和HSP90 （P= 0.0040，重度）基因表达量均升高。我们得出结论，毛囊中HSP基因表达为评估HS提供了精确和准确的数据，可以被认为是在外部和气候室中维持的韩宇犊牛HS的新指标。
Heat shock proteins (HSPs) consist of highly preserved stress proteins that are expressed in response to stress. Two studies were carried out to investigate whether HSP genes in hair follicles from beef calves can be suggested as indicators of heat stress (HS). In study 1, hair follicles were harvested from three male Hanwoo calves (aged 172.2 +/- 7.20 days) on six dates over the period of 10 April to 9 August 2017. These days provided varying temperature-humidity indices (THIs). In study 2, 16 Hanwoo male calves (aged 169.6 +/- 4.60 days, with a BW of 136.9 +/- 6.23 kg) were maintained (4 calves per experiment) in environmentally controlled chambers. A completely randomized design with a 2 x 4 factorial arrangement involving two periods (thermoneutral:TN; HS) and four THI treatment groups (threshold: THI = 68 to 70; mild: THI = 74 to 76; moderate THI = 81 to 83; severe: THI = 88 to 90). The calves in the different group were subjected to ambient temperature (22 degrees C) for 7 days (TN) and subsequently to the temperature and humidity corresponding to the target THI level for 21 days (HS). Every three days (at 1400 h) during both the TN and HS periods, the heart rate (HR) and rectal temperature (RT) of each individual were measured, and hair follicles were subsequently collected from the tails of each individual. In study 1, the high variation (P< 0.0001) in THI indicated that the external environment influenced the HS to different extents. The expression levels of the HSP70 and HSP90 genes at the high-THI level were higher (P= 0.0120,P= 0.0002) than those at the low-THI level. In study 2, no differences in the THI (P= 0.2638), HR (P= 0.2181) or RT (P= 0.3846) were found among the groups during the TN period, whereas differences in these indices (P< 0.0001,P< 0.0001 andP< 0.0001, respectively) were observed during the HS period. The expression levels of the HSP70 (P= 0.0010, moderate;P= 0.0065, severe) and HSP90 (P= 0.0040, severe) genes were increased after rapid exposure to heat-stress conditions (moderate and severe levels). We conclude that HSP gene expression in hair follicles provides precise and accurate data for evaluating HS and can be considered a novel indicator of HS in Hanwoo calves maintained in both external and climatic chambers.