Molecular mechanisms underlying sexual precocity in Chinese mitten crab (Eriocheir sinensis): aldh1a1 regulates retinol metabolism via miRNAs in the hepatopancreas

Precocial Eriocheir sinensis , showing advanced sexual maturity, are a serious impediment to crab industry. The aim of this study was to identify miRNAs and its related pathways involved in regulation of precocity in E. sinensis . High-throughput sequencing was used to evaluate hepatopancreas of precocious and normal E. sinensis at the same period. A total of 101 differentially expressed miRNAs were identified as candidate target genes. KEGG analysis revealed retinol metabolism may contribute to the regulation of gonadogenesis. Aldehyde dehydrogenase 1 family member A1 ( aldh1a1 ) was identified as the core gene in the retinol metabolism by gene expression, and subsequently, gene cloning was performed to further explore its function. The a ldh1a1 gene was 1740 bp, including a 189 bp 5′ untranslated region (UTR), 75 bp 3′ UTR and a 1476 bp open-reading frame, encoding 491 amino acids. The corresponding protein is 87.98 % homologous in Portunus trituberculatus . The expression of aldh1a1 was highest in ovary, and then in the hepatopancreas. In addition, dual-luciferase reporter assay indicated that there was negative correlation between NW_020868524.1_2213 and aldh1a1 . NW_020868524.1_2213 agomir treatment in the normal group increased testosterone and estradiol levels significantly, down-regulated aldh1a1 expression, and activated the retinol metabolism. By contrast, the administration of NW_020868524.1_2213 antagomir after a short-term induction of retinol resulted in increase in aldh1a1 expression, decrease in sex hormone levels, and inhibition in retinol metabolism. In short, NW_020868524.1_2213 in the hepatopancreas could activate the retinol metabolic pathway via aldh1a1 , thus regulating precocious and gonadal development in E. sinensis. These findings would provide a potential pathway for decreasing crab precocity in practice. • Retinol metabolism pathway can regulate sexual maturity in Eriocheir sinensis . • Aldh1a1 might contribute to precocious puberty and gonadal development in E. sinensis. • Aldh1a1 regulates retinol metabolism via NW_020868524.1_2213 in the hepatopancreas.