Department of Veterinary Physiology, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, UP, India.
Department of Veterinary Physiology, College of Veterinary Science and Animal Husbandry, Veterinary University, Mathura, 281001, UP, India.
J Therm Biol. 2021 Apr;97:102904. doi: 10.1016/j.jtherbio.2021.102904. Epub 2021 Mar 10.
The present experiment was aimed to study differential expression of miRNAs and related mRNAs during heat stress (HS) in buffalo heifers. Twelve Murrah buffalo heifers aged between 1.5 and 2.0 years, weighting between 250 and 300 Kg were randomly assigned into two equal groups. The animals were kept in the psychrometric chamber under Thermo-neutral (TN; THI = 72) and HS (THI = 87-90) conditions for 6 h every day between 1000 and 1600 h for 21 days. The blood sampling was done at 1500 h on 15th day of the experiment and physiological parameters viz. pulse rate (PR), respiratory rate (RR) and rectal temperature (RT) were recorded at 1500 h on day -5, -3, -1, 0, +1, +3, +5 with respect to blood sampling. PBMCs were used for extraction of miRNAs and total RNA; and first strand cDNA was synthesized. qPCR was performed for relative gene expression studies. Physiological, hematological (erythrocytic indices), biochemical (triglycerides, urea, ALT, AST, LDH), redox (SOD, ROS) and endocrine parameters (T) altered significantly (P < 0.05) during HS as compared to TN. Out of eight targeted miRNAs only four were expressed in buffalo heifers. The relative expression of bta-mir-142, bta-mir-1248 and bta-mir-2332 was significantly (P < 0.05) up-regulated whereas expression of bta-mir-2478 was significantly (P < 0.05) down-regulated during HS as compared to TN. The relative expression of the predicted target genes i.e. HSF1, HSP60, HSP70, HSPA8 and HSP90 were significantly (P < 0.05) up-regulated whereas HSF4 expression was significantly (P < 0.05) down-regulated during HS as compared to TN. It can be concluded that a THI of 87-90 could lead to a moderate HS in buffalo heifers. Differential expression studies of miRNAs and related mRNAs in present study deciphers the role of miRNAs in the heat tolerance in buffalo heifers.
本实验旨在研究水牛小母牛在热应激（HS）过程中 miRNA 和相关 mRNA 的差异表达。12 头 1.5-2.0 岁、体重 250-300 公斤的摩拉水牛小母牛被随机分为两组。这些动物在温湿度计室内的热中性（TN；THI=72）和 HS（THI=87-90）条件下，每天 1000 到 1600 小时，每天进行 6 小时的处理，持续 21 天。在实验的第 15 天 1500 小时进行采血，在采血前 5 天、3 天、1 天、0 天、+1 天、+3 天、+5 天的 1500 小时记录生理参数，即脉搏率（PR）、呼吸率（RR）和直肠温度（RT）。使用 PBMC 提取 miRNA 和总 RNA，并合成第一链 cDNA。进行 qPCR 以进行相对基因表达研究。与 TN 相比，HS 期间生理、血液学（红细胞指数）、生物化学（甘油三酯、尿素、ALT、AST、LDH）、氧化还原（SOD、ROS）和内分泌参数（T）发生显著变化（P<0.05）。在水牛小母牛中，有 8 个靶向 miRNA 中只有 4 个表达。bta-mir-142、bta-mir-1248 和 bta-mir-2332 的相对表达水平在 HS 期间显著上调（P<0.05），而 bta-mir-2478 的表达水平在 HS 期间显著下调（P<0.05）与 TN 相比。预测靶基因 HSF1、HSP60、HSP70、HSPA8 和 HSP90 的相对表达水平在 HS 期间显著上调（P<0.05），而 HSF4 的表达水平在 HS 期间显著下调（P<0.05）与 TN 相比。可以得出结论，THI 为 87-90 可能导致水牛小母牛发生中度热应激。本研究中 miRNA 及其相关 mRNA 的差异表达研究揭示了 miRNA 在水牛小母牛耐热性中的作用。
