Integrated omics analysis reveals the effect of feeding scarcity on the lipid metabolism and apoptosis in Nibea coibor

Abstract

Food scarcity was a crucial challenge to fish in natural waters, necessitating a complex adaptive process for them to cope with. This study estimated the effects of four different feeding strategies (daytime feeding, DF; intermittent fasting, IF; continuous fasting, CF; nighttime feeding, NF) on the growth, metabolism, and health of Nibea coibor. The lowest weight gain rate and steatosis degree occurred in the CF group, which had the highest bacterial load in the liver and the lowest survival rate after Vibrio harveyi infection. The IF group had the highest serum GLU, LAC, and COR levels and the lowest hepatic bacterial loads post V. harveyi challenge. The NF group had higher serum GLU level (P < 0.05) and lower survival rate compared to DF. Notably, the integrated analysis of transcriptome and metabolome screened out significantly differential genes (dgke, pla2g12b, axin2) and metabolite (Glycerophosphocholine), which were all involved in lipid metabolism and downregulated in CF (P < 0.05). The correlation analysis of phenotypic indicators with the transcriptome and metabolome showed that gadd45 and L-carnitine were positively and negatively correlated with bacterial infection resistance, respectively. In general, this study suggested fasting influenced weight gain and bacterial infection resistance of N. coibor, through regulating genes and metabolites related to lipid metabolism and apoptosis, providing valuable reference significance on the impact of feeding rhythm on fish.