Effect of Acute Heat Stress on Protein Expression and Histone Modification in The Adrenal Gland of Male Layer-Type Country Chickens

The adrenal gland responds to heat stress by epinephrine and glucocorticoid release to alleviate the adverse effects. This study investigated the effect of acute heat stress on the protein profile and histone modification in the adrenal gland of layer-type country chickens. A total of 192 30-week-old roosters were subject to acute heat stress. A resistant group and a susceptible group were identified according to body temperature change after heat stress. Adrenal glands were collected for global protein expression and histone modification analysis. The results indicated that fatty acid amide hydrolase and parathymosin were downregulated, whereas somatostatin, steroidogenic acute regulatory protein, hydroxy-δ-5-steroid dehydrogenase, 3 beta- and steroid δ-isomerase 1, and prostaglandin E synthase 3 were upregulated in the resistant group. Histone modification analysis identified 115 histone markers. The tri-methylation state of histone H3 lysine 27 (H3K27me3) was significantly more abundant in the susceptible group and showed positive crosstalk with K36me and K37me in the H3 tails. Roosters in the heat-resistant group exhibited lower hypothalamus–pituitary–adrenal axis activity but higher reactivity to maintain body temperature homeostasis. Alteration of adrenal H3K27me3 level was associated with the endocrine function of adrenal H3K27me3 and may have contributed to the thermotolerance of chickens.