Partial sequence characterization and ontogenetic expression of genes involved in lipid metabolism in the tropical gar (Atractosteus tropicus)

The tropical gar (Atractosteus tropicus) is an economically and socially important freshwater fish species from southeastern Mexico, with high aquaculture potential. This study determined the expression of acetyl-CoA carboxylase (ACC1), fatty acid synthase (FAS), and carnitine palmitoyl transferase 1 (CPT1C) in several tissues of adult specimens, as well as in early ontogeny stages of tropical gar. Partial sequences of all genes were obtained for brain, liver, muscle, mesenteric adipose, kidney, testis, gill, and heart in males. Specific qPCR primers were used to compare the expression between tissues and also during larviculture, starting with embryos (0 days after hatching, [DAH]), and at 5, 10, 15, 20, 25, and 30 DAH. Mesenteric adipose tissue, liver, and muscle showed maximum FAS, ACC1, and CPT1C expression. Additionally, the highest expression of lipogenic genes was detected in embryos (0 DAH), decreasing between 5 and 10 DAH, then increasing at 15 DAH, and ultimately decreasing again from 20 DAH onwards. Based on these results, it can be concluded that genes encoding ACC1, FAS, and CPT1C are expressed differentially across tissues of tropical gar adults, and are regulated during larval development.