Divergent molecular responsive mechanism of female and male spotted scat (Scatophagus argus) liver to 17β-estradiol revealed by the comparative transcriptome analysis

Spotted scat (Scatophagus argus), an economically significant marine fish species, is widely distributed along the coasts of Guangxi, Taiwan and Guangdong Province in China. It exhibits sexual growth dimorphism, with females exhibiting a faster growth rate and larger size than males. The critical metabolic organ liver plays an important role in regulating body growth and reproduction processes, which that are influenced by estrogens. In this study, the molecular mechanisms of 17-estradiol (E2) regulates body growth and reproduction in livers were investigated by transcriptome sequencing, after fed 2-year-old spotted scat with E2-containing baits for 30 days. Transcriptome analysis identified 218, 1949, 548, and 1718 differentially expressed genes (DEGs) (FDR < 0.05 and |log2(FC)| ≥ 1) in livers of spotted scat across the Ctrl-ML vs. Ctrl-FL, E2-ML vs. E2-FL, E2-ML vs. Ctrl-ML, and E2-FL vs. Ctrl-FL groups, respectively. The amino sugar and nucleotide sugar metabolism pathway was significantly influenced in females by E2. While fatty acid metabolism, arginine and proline metabolism were significantly enriched in males. Several genes metabolic (acsl5, gpx1b, and nots), growth and reproduction-related genes (igfs, vtgs, erα, and zps) were responded to E2 in a gender-specific manner. Thus, the livers of females appeared to be more sensitive to E2 feeding than males, and the responsive mechanisms of spotted scat livers to E2 were gender-specific. These findings will provide a foundation for understanding the molecular regulation of estrogen in fish growth and reproduction within the liver, and will also offer theoretical evidence for the artificial cultivation of spotted scat.