Transcriptomic and epigenomic network analysis reveals chicken physiological reactions against heat stress

Global warming is expected to result in larger temperature fluctuations by which heat stress may become an important stressor for animals, affecting health and productivity. Animals can cope with and adapt to heat stress by changing their physiology. To investigate general physiological reactions to heat stress in muscle and heart tissues of chickens we combined results from three independent experiments. Two experiments studied the transcriptome profiles of heart and muscle tissues of mature chickens using heat stress adapted and nonadapted chickens. One experiment studied the epigenome changes of heat stress during chicken egg incubation. In all three datasets epigenome changes were important biological response mechanisms, which may underlie genome-wide regulation of the affected biological mechanisms. Pre and postnatal heat stress reaction showed changed expression of genes related to metabolic rate, energy, and protein metabolism. Furthermore, tissue integrity may be affected due to changed cell−cell contacts, vascularization, and growth reduction.