FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

Neuropeptide F (NPF) is one of the homologs of vertebrate neuropeptide Y and mainly regulates food intake, metabolism, reproduction, and stress reaction in invertebrate. Feeding regulation genes are widely distributed in the central and peripheral nervous systems and influence appetite and feeding behavior via the inter-regulatory relationship between the two systems. This experiment investigated the effect of the expression of a feeding regulation gene, NPF, on Litopenaeus vannamei feeding behaviors and examined its expression in different tissues of shrimp. The results of semi-quantitative RT-PCR analysis showed that NPF gene was dominantly expressed in ganglia and brain. Under the fixed feeding periodicity, the NPF gene expression level significantly increased one hour before feeding, and gradually decreased after feeding. Such attractants as garlic extract, dimethyl propiothetin (DMPT), and trimethylamine N–oxide (TMAO) can significantly promote NPF gene expression in white shrimp. A combined use of DMPT and TMAP has a synergistic effect. TMAO utilization before feeding can significantly increase NPF gene expression in white shrimp (p < 0.05), shortening the time they need to search for forage and improving food intake. In this study, we have demonstrated that attractants can improve appetite and ingestion by effecting the expression of NPF gene and showed the relation of NPF to feeding behavior of crustaceans, which makes NPF an important feed regulation gene in white shrimp.