Figure 9.

Transcript expression of leptin and leptin receptor in the liver of goldfish with short-term exposure to winter temperature (15°C). Water temperature for goldfish acclimated at 28°C was reduced to 15°C over a 24-h period using a cooling system linked with the water tank. The liver was harvested from individual fish at different time points before and after the activation of the cooling system (as indicated by gray triangle). Total RNA was isolated, reversely transcribed and used for real-time PCR for respective gene targets, including (A) β actin, (B) leptin I, (C) leptin II and (D) leptin receptor. Parallel experiment with goldfish maintained at 28°C water without activation of the cooling system was used as the control treatment. For our time course study, the data obtained (mean ± SEM, n = 12) were analyzed with two-way ANOVA followed by Tukey test. Difference between groups was considered as significant at p < 0.05 (^*p < 0.05, ^**p < 0.01, and ^***p < 0.001).