Fig. 5.

Effects of chronic cold stress on the hsp90, hsp70, hsp60, hsp40, and hsp27 genes mRNA expression in hearts of chickens. a–e The mRNA expression of hsp90, hsp70, hsp60, hsp40, and hsp27 genes, respectively. In the chronic cold stress experiment, relative mRNA levels of the hsps genes were detected by qPCR; the relative mRNA levels from the 5-, 10-, and 20-day control group were used as the reference values in a–e. Each value represented the mean ± SD of six individuals. Asterisk, significant differences (P < 0.05) between the control group and the stress group at the same time point