Expression Patterns of Copper/Zinc Superoxide Dismutase (SOD1) in Quail Embryonic Tissues Under in Ovo and Ex Ovo Conditions

Temperature fluctuations can act as stressors affecting embryonic development and cellular homeostasis. This study examined the effects of preincubation at 22°C (P22) or 30°C (P30) on quail embryos under in ovo and ex ovo conditions, focusing on the expression of the antioxidant enzyme superoxide dismutase (SOD1) in selected tissues. Under in ovo incubation, SOD1 expression was significantly upregulated in both liver and heart at P22 and P30, with the highest expression observed in the liver at P30. In contrast, under ex ovo conditions, SOD1 expression was significantly reduced in the liver at P22 but partially restored at P30. In the heart, it was not significantly increased at P22 but slightly decreased at P30. These findings demonstrate tissue- and condition-specific regulation of SOD1 and suggest that in ovo preincubation supports robust antioxidant defence, whereas ex ovo culture imposes complex stress responses.