Molecular characterization and expression analysis of the IFN-gamma and NOD1 gene in tropical gar Atractosteus tropicus

. The tropical gar (Atractosteus tropicus), a freshwater species mostly found in swamps, has been used for human consumption for several generations. In this study, the expression of interferon-gamma (ifn-gamma) and domain nucleotide-binding oligomerization (nod1) involved in the immune system was evaluated in different tissues such as the brain, heart, spleen, liver, pancreas, kidney, intestine, and gonad in wild and captive adult organisms and during early ontogeny. Specific quantitative polymerase chain reaction (qPCR) primers were used to compare the expression between tissues and during larviculture, starting with embryos (0 days after hatching, [DAH]) and at 5, 10, 15, 20, 25, and 30 DAH. The intestine, pancreas, and liver showed maximum ifn-gamma and nod1 expression. Additionally, the expression of genes ifn-gamma and nod1 was detected in embryos (0 DAH), decreasing between 5 and 10, then increasing at 25 and 30 DAH. Based on these results, it can be concluded that genes encoding ifn-gamma and nod1 are expressed differentially across tissues of tropical gar adults and are regulated during larval development.