Expression of leptin-like peptide (LLP) mRNA in channel catfish (Ictalurus punctatus) is induced by exposure to Edwardsiella ictaluri but is independent of energy status

► Catfish leptin-like protein (LLP) was structurally similar to human cytokines. ► Catfish LLP shared little sequence similarity with mammalian and fish leptin. ► Catfish LLP mRNA was highly expressed in liver, spleen, and trunk kidney. ► Brain and hepatic LLP mRNA expression was unaffected by changes in energy status. ► Expression of LLP mRNA was increased after exposure to Edwardsiella ictaluri.