Molecular Cloning of the scd1 Gene and Its Expression in Response to Feeding Artificial Diets to Mandarin Fish (Siniperca chuatsi)

<b>Background/Objectives</b>: Stearoyl-coenzyme A desaturase 1 (SCD1) plays a crucial role in fatty acid metabolism. However, its roles in the feeding habit transformation of mandarin fish (<i>Siniperca chuatsi</i>) remain largely unknown. <b>Methods:</b> Juvenile mandarin fish (10.37 ± 0.54)g were trained to feed on an artificial diet and then divided into artificial diet feeders and nonfeeders according to their feed preference. Afterwards, the <i>scd1</i> gene of mandarin fish (<i>Sc-scd1</i>) was identified and characterized, and its transcription difference was determined between <i>S. chuatsi</i> fed live artificial diets and those fed prey fish. <b>Results:</b> Our results show that <i>Sc-scd1</i> coding sequence is 1002 bp long, encoding 333 amino acids. The assumed <i>Sc</i>-SCD1 protein lacks a signal peptide, and it contains 1 N-linked glycosylation site, 24 phosphorylation sites, 4 transmembrane structures, and 3 conserved histidine elements. We found that <i>Sc</i>-SCD1 exhibits a high similarity with its counterparts in other fish by multiple alignments and phylogenetic analysis. The expression level of <i>Sc-scd1</i> was detected with different expression levels in all tested tissues between male and female individuals fed either live prey fish or artificial diets. <b>Conclusions:</b> In particular, the <i>Sc-scd1</i> expression level was the highest in the liver of both male and female mandarin fish fed artificial diets, indicating that <i>scd1</i> genes may be associated with feed adaption of mandarin fish. Taken together, our findings offer novel perspectives on the potential roles of <i>scd1</i> in specific domestication, and they provide valuable genetic information on feeding habits for the domestication of mandarin fish.