Abdelli Nedra, Ramser Alison, Greene Elizabeth S, Beer Lesleigh, Tabler Travis W, Orlowski Sara K, Pérez José Francisco, Solà-Oriol David, Anthony Nicholas B, Dridi Sami
Animal Nutrition and Welfare Service, Department of Animal and Food Sciences, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Department of Poultry Science, University of Arkansas, Fayetteville, AR, United States.
Front Physiol. 2021 Oct 21;12:733134. doi: 10.3389/fphys.2021.733134. eCollection 2021.
Heat stress (HS) has been reported to disrupt nutrient digestion and absorption in broilers. These effects may be more prominent in fast-growing chickens due to their high metabolic activity. However, the underlying molecular mechanisms are not yet fully elucidated. Hence, the current study aimed to evaluate the effect of chronic HS on jejunal nutrient transport in slow- (Athens Canadian Random Bred, ACRB from 1950), moderate- (The 1995 random bred, 95RAN), rapid- (modern broilers, modern random bred, MRB) growing birds and their ancestor wild jungle fowl (JF). One-day male chicks ( = 150/line) were placed by line in environmentally controlled chambers and kept under the same industry-standard environmental conditions until d28. On d29, an 8-h daily cyclic HS (36°C) was applied to half of the chambers, which lasted until d55, while keeping the rest under thermal neutral (TN, 24°C) conditions. Jejunum tissues were collected for morphology assessment and molecular analysis of carbohydrate-, amino acid-, and fatty acid-transporters. MRB exhibited the highest body weight (BW) followed by 95RAN under both conditions. HS decreased feed intake (FI) in MRB and 95RAN, which resulted in lower BW compared to their TN counterparts; however, no effect was observed in ACRB and JF. MRB showed a greater villus height (VH) to crypt depth (CD) ratio under both environmental conditions. Molecular analyses showed that glucose transporter (GLUT) 2, 5, 10, and 11 were upregulated in MRB compared to some of the other populations under TN conditions. HS downregulated GLUT2, 10, 11, and 12 in MRB while it increased the expression of GLUT1, 5, 10, and 11 in JF. GLUT2 protein expression was higher in JF compared to ACRB and MRB under TN conditions. It also showed an increase in ACRB but no effect on 95RAN and MRB under HS conditions. ACRB exhibited greater expression of the EAAT3 gene as compared to the rest of the populations maintained under TN conditions. HS exposure did not alter the gene expression of amino acid transporters in MRB. Gene expression of CD36 and FABP2 was upregulated in HS JF birds. Protein expression of CD36 was downregulated in HS JF while no effect was observed in ACRB, 95RAN, and MRB. Taken together, these data are the first to show the effect of HS on jejunal expression of nutrient transporters in three broiler populations known to represent 70 years of genetic progress in the poultry industry and a Red Jungle Fowl population representative of the primary ancestor of domestic chickens.
据报道，热应激（HS）会扰乱肉鸡的营养消化和吸收。由于其高代谢活性，这些影响在快速生长的鸡中可能更为突出。然而，其潜在的分子机制尚未完全阐明。因此，本研究旨在评估慢性热应激对慢速生长（1950年雅典加拿大随机品系，ACRB）、中度生长（1995年随机品系，95RAN）、快速生长（现代肉鸡，现代随机品系，MRB）的鸡及其祖先野生原鸡（JF）空肠营养物质转运的影响。将一日龄雄性雏鸡（每个品系150只）按品系放置在环境控制的鸡舍中，并在相同的行业标准环境条件下饲养至第28天。在第29天，对一半的鸡舍施加每天8小时的循环热应激（36°C），持续到第55天，而其余鸡舍保持在热中性（TN，24°C）条件下。收集空肠组织进行形态学评估以及碳水化合物、氨基酸和脂肪酸转运蛋白的分子分析。在两种条件下，MRB的体重（BW）最高，其次是95RAN。热应激降低了MRB和95RAN的采食量（FI），导致其体重低于处于热中性条件下的同品系鸡；然而，在ACRB和JF中未观察到影响。在两种环境条件下，MRB的绒毛高度（VH）与隐窝深度（CD）之比都更大。分子分析表明，与处于热中性条件下的其他一些群体相比，MRB中的葡萄糖转运蛋白（GLUT）2、5、10和11上调。热应激使MRB中的GLUT2、10、11和12下调，而在JF中增加了GLUT1、5、10和11的表达。在热中性条件下，JF中的GLUT2蛋白表达高于ACRB和MRB。在热应激条件下，ACRB中的GLUT2蛋白表达也增加，但对95RAN和MRB没有影响。与处于热中性条件下的其他群体相比，ACRB中EAAT3基因的表达更高。热应激暴露并未改变MRB中氨基酸转运蛋白的基因表达。热应激条件下的JF鸡中CD36和FABP2的基因表达上调。热应激条件下JF中的CD36蛋白表达下调，而在ACRB、95RAN和MRB中未观察到影响。综上所述，这些数据首次表明了热应激对三个肉鸡群体空肠营养物质转运蛋白表达的影响，这三个群体代表了家禽业70年的遗传进展，还有一个代表家鸡主要祖先的红原鸡群体。
