Alteration of HSF3 and HSP70 mRNA expression in the tissues of two chicken breeds during acute heat stress.

This study aimed to estimate changes in HSF3 and HSP70 mRNA expression in stress-sensitive tissues of 2 chicken breeds during acute heat stress. Lingshan chickens (LSC) and White Recessive Rock (WRR) (24 chickens of each breed) were randomly divided into 4 groups (0, 2, 3, and 6 h of heat treatment). With increasing heat treatment time, both HSF3 and HSP70 expression first declined and then showed a significant increase in both breeds. However, HSP70 expression decreased in the heart following 6 h of heat treatment, whereas HSF3 expression continued to increase. After 2 h of heat treatment, HSF3 expression was significantly higher in the brain and leg muscle of LSC compared to WRR (P < 0.05, P < 0.01). In comparison, HSP70 expression was significantly higher in the liver and leg muscle of WRR compared to LSC (P < 0.01, P < 0.05). After 3 h of heat treatment, HSF3 expression was significantly higher in the brain and leg muscle of LSC compared to WRR (P < 0.01). In comparison, HSP70 expression was significantly higher in the liver and heart of LSC compared to WRR (P < 0.01). These results indicate that the expression of HSF3 and HSP70 mRNA in LSC and WRR exhibit species-specific and tissue-specific differences during heat treatment.