Knockdown of cytochrome P450 1 A (cyp1a) gene suppresses growth and oxygen tolerance in zebrafish

Cyp1a (cytochrome P450 1 A) is critical for metabolizing endogenous substances and environmental chemicals. In this study, a zebrafish strain KI ( cyp1a:mcherry ), exhibiting low cyp1a gene expression, was compared with wild-type zebrafish (WT) to investigate the effects of cyp1a on growth and hypoxia tolerance. The results demonstrated that low cyp1a expression significantly inhibited zebrafish growth and reduced hypoxia tolerance. Specifically, KI zebrafish exhibited slower growth rates and higher sensitivity to low oxygen conditions compared to WT. These physiological phenotypes directly link low cyp1a expression to impaired growth and reduced environmental adaptation. Transcriptomic analysis revealed potential mechanisms underlying these effects, including up-regulation of digestive system-related genes (e.g., cpa1 , cpb1 ) and dysregulation of pathways involved in detoxification, stress response, and steroid biosynthesis. These findings highlight the importance of maintaining normal cyp1a expression for healthy growth and environmental adaptation in zebrafish.