THE SEQUENCE CHARACTERISTICS OF LPL-A IN COMMON CARP (CYPRINUS CARPIO) AND THE EFFECTS OF ITS OVEREXPRESSION ON FAT DEPOSITION

To investigate the effects of overexpressing lipoprotein lipase a gene (<italic>lpl-a</italic>) in common carp (<italic>Cyprinus carpio</italic>) on fat deposition patterns and lipid metabolism-related genes expression, we analyzed the sequence and structural characteristics of the carp <italic>lpl-a</italic> and examined its tissue distribution using quantitative Real-time (qPCR) in five internal tissues: abdominal fat, liver, kidney, muscle, and intestine. The <italic>lpl-a</italic> overexpression plasmid vector was constructed by homologous recombination and introduced into zebrafish (<italic>Danio rerio</italic>) and carp liver cells. The impacts of <italic>lpl-a</italic> overexpression on total cholesterol (T-CHO), triglyceride (TG) levels, and expressions of lipid metabolism marker genes (<italic>ppar γ</italic>, <italic>fabp 3</italic>, <italic>pnpla 2</italic>, etc.) were assessed in zebrafish (individual level) and carp hepatocytes (cell level). Results showed that the carp <italic>lpl-a</italic> was predicted to encode a 507-amino acid protein with 7 open reading frames (ORFs), and it demonstrated high evolutionary conservation in osteichthyes. Tissue-specific expression analysis revealed significantly higher <italic>lpl-a</italic> transcript levels in abdominal fat, liver, and kidney compared to muscle and intestine (<italic>P</italic>&lt;0.05). In zebrafish, microinjection of the <italic>lpl-a</italic> overexpression vector resulted in an approximately 7-fold increase in muscle T-CHO and a 1-fold increase in both T-CHO and TG in liver, accompanied by upregulation of <italic>lpl-a</italic>, <italic>ppar γ</italic>, and <italic>fabp 3</italic> (<italic>P</italic>&lt;0.05). In carp hepatocytes, transfection with the <italic>lpl-a</italic> construct for 72h significantly increased <italic>lpl-a</italic> and lipolytic gene <italic>pnpla</italic><italic>2</italic> expressions (<italic>P</italic>&lt;0.05). Altogether, these findings demonstrate that overexpression of <italic>lpl-a</italic> induced distinct lipid metabolism regulations at individual (enhanced muscle fat storage and hepatic lipid accumulation) and cellular (activated lipolysis and inhibited lipogenesis) levels, providing theoretical insights for targeting <italic>lpl-a</italic> to modulate lipid deposition in economically important aquatic animals.