{"title":"Novel insights into heat tolerance via metabolomic analysis in Tibetan sheep","authors":"Qiang-Jun Wang , Zhu Meng , Jia-Hong Chen, Chun-Huan Ren, Zi-Jun Zhang","doi":"10.1016/j.jtherbio.2025.104230","DOIUrl":null,"url":null,"abstract":"<div><div>Tibetan sheep are highly adaptable to cold and hypoxic environments, allowing them to thrive on the Qinghai‒Tibet Plateau. Although many studies have investigated the mechanisms underlying their cold tolerance and hypoxia adaptation, it is still unclear how Tibetan sheep cope with the challenges of heat stress (HS) when raised in southern China. In this study, Tibetan sheep and heat-tolerant breeds (Hu sheep and Huanghuai sheep) were selected, and we conducted physiological observations, biochemical measurements, and metabolomic analysis on serum from a nonheat stress (NH) group, where the temperature–humidity index (THI) was 59.13, and a heat-stressed group (THI = 82.78). The results revealed that HS significantly increased the rectal temperature, respiratory rate, and heart rate of Tibetan sheep, and these values were significantly greater than those in the heat-tolerant breeds. Serum antioxidant indices revealed that catalase activity, total antioxidant capacity, and total superoxide dismutase activity were significantly lower in Tibetan sheep than in Hu sheep under HS. Metabolomic analysis revealed that HS reduced the levels of serum antioxidant metabolites, such as creatine, ornithine, l-arginine, and guanosine, and increased the levels of the oxidative stress marker metabolite 3-nitrotyrosine in Tibetan sheep. Additionally, the ratio of serum antioxidant metabolites to 3-nitrotyrosine in Tibetan sheep was significantly lower than that in heat-tolerant breeds, and these ratios were correlated with physiological parameters. Therefore, these results suggest that Tibetan sheep are relatively sensitive to HS.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"132 ","pages":"Article 104230"},"PeriodicalIF":2.9000,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of thermal biology","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0306456525001871","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Tibetan sheep are highly adaptable to cold and hypoxic environments, allowing them to thrive on the Qinghai‒Tibet Plateau. Although many studies have investigated the mechanisms underlying their cold tolerance and hypoxia adaptation, it is still unclear how Tibetan sheep cope with the challenges of heat stress (HS) when raised in southern China. In this study, Tibetan sheep and heat-tolerant breeds (Hu sheep and Huanghuai sheep) were selected, and we conducted physiological observations, biochemical measurements, and metabolomic analysis on serum from a nonheat stress (NH) group, where the temperature–humidity index (THI) was 59.13, and a heat-stressed group (THI = 82.78). The results revealed that HS significantly increased the rectal temperature, respiratory rate, and heart rate of Tibetan sheep, and these values were significantly greater than those in the heat-tolerant breeds. Serum antioxidant indices revealed that catalase activity, total antioxidant capacity, and total superoxide dismutase activity were significantly lower in Tibetan sheep than in Hu sheep under HS. Metabolomic analysis revealed that HS reduced the levels of serum antioxidant metabolites, such as creatine, ornithine, l-arginine, and guanosine, and increased the levels of the oxidative stress marker metabolite 3-nitrotyrosine in Tibetan sheep. Additionally, the ratio of serum antioxidant metabolites to 3-nitrotyrosine in Tibetan sheep was significantly lower than that in heat-tolerant breeds, and these ratios were correlated with physiological parameters. Therefore, these results suggest that Tibetan sheep are relatively sensitive to HS.
期刊介绍:
The Journal of Thermal Biology publishes articles that advance our knowledge on the ways and mechanisms through which temperature affects man and animals. This includes studies of their responses to these effects and on the ecological consequences. Directly relevant to this theme are:
• The mechanisms of thermal limitation, heat and cold injury, and the resistance of organisms to extremes of temperature
• The mechanisms involved in acclimation, acclimatization and evolutionary adaptation to temperature
• Mechanisms underlying the patterns of hibernation, torpor, dormancy, aestivation and diapause
• Effects of temperature on reproduction and development, growth, ageing and life-span
• Studies on modelling heat transfer between organisms and their environment
• The contributions of temperature to effects of climate change on animal species and man
• Studies of conservation biology and physiology related to temperature
• Behavioural and physiological regulation of body temperature including its pathophysiology and fever
• Medical applications of hypo- and hyperthermia
Article types:
• Original articles
• Review articles