Effection of MC-LR on appeptite-regulating genes in zebrafish

• 1、College of Huazhong Agricultural University, Wuhan 430070

Abstract：Dense blooms of cyanobacterial (blue-green algae) are one of the consequences of the increasing eutrophication in many waters worldwide. With frequent occurrence of cyanobacterial blooms in recent years, cyanotoxins have become a great threat to aquatic animals and human health. Among cyanotoxins, microcystins (MC) are the most common and toxic. Microcystin-leucine-arginine (MC-LR) is the most toxic and the most commonly encountered variant of microcystins (MCs) in aquatic environment, and it has the potential for disrupting appetite of fish, but the molecular mechanisms underlying this process have not yet been clarified. In the present study, zebrafish were exposed to varied does of MC-LR groups (0, 0.3, 3, and 30μg/L).After 12 weeks, RNA was extracted from the brain samples and reverse transcribed into cDNA. Fluorescence quantitative PCR reactions were performed to detect the expression of appetite-related genes and assess the change of zebrafish appetite. The results showed that the expression of appetite-promoting genes decreased at low dose MC-LR group, while appetite-promoting genes increased at high dose MC-LR group. In addition, MC-LR could down-regulate the expression of appetite-inhibiting genes at a lower concentration, but it will up-regulate them in a higher concentration. We may draw the conclusion that MC-LR could disorder appetite-related genes, which might eventually interfer ingestion of zebrafish.

Keywords： Microcystin zebrafish appetite-promoting genes appetite-inhibiting genes