Transcriptomic analysis reveals sexual dimorphism in lipid metabolism within largemouth bass (Micropterus salmoides) fed the high-fat diet

Abstract

The study presented the differential responses of male and female largemouth bass fed a high-fat diet, focusing on growth performance, hepatic transcriptomics, and lipid metabolism. The high-fat diet, 50.23 % crude protein and 19.46 % crude fat, was formulated and fed to female and male largemouth bass for 73 days separately. Growth parameters, such as final weight, weight gain (WG) and specific growth rate (SGR), demonstrated superior performance in males compared to females fed the high-fat diet. Hepatic transcriptomic analysis between the sexes under high-fat diet revealed totally 267 differentially expressed genes (DEGs), of which 132 were up-regulated and 135 down-regulated. Notably, genes implicated in lipid biosynthesis, such as elovl5, pap, aacs, hmgcra, fdft1, ebp, and dhcr24, were found to be down-regulated in males and are enriched in metabolic pathways. This suggests a sex-dependent modulation of lipid metabolism. Furthermore, the study revealed a stark contrast in hepatic mRNA expression levels of genes pivotal for lipid anabolism, with acc1, pparγ, srebf1, fasn, and scd being more highly expressed in females compared to males. Conversely, genes associated with lipid catabolism, including cpt1 and hsl, showed elevated expression in males. These findings underscore the interplay between sex, diet, and metabolic regulation in largemouth bass. The study's contributions to our understanding of physiological variances between male and female largemouth bass under high-fat diet are significant, offering valuable insights for the nutritional strategies to accommodate the metabolic needs of both sexes.