Adaptation of the in vivo respiratory burst assay for fathead minnow larvae (Pimephales promelas)

Initial innate immune responses such as the respiratory burst response of phagocytes present the first line of defense in response to exposure to pathogens. Several respiratory burst assays have been developed in mammals, cell cultures, and whole zebrafish embryos as a reliable indicator of the innate immune response of a host, and these assays are being used to screen various environmental contaminants for their immunotoxic potential. While zebrafish are a common laboratory fish used in toxicology studies geared towards human health effects, fathead minnows are commonly used as an ecotoxicological indicator species for North America. In this technical note, we describe how we adapted the zebrafish in vivo respiratory burst assay for use in fathead minnow larvae. This assay provides promising expansion of using in vivo respiratory burst responses in different species of larval fish for future comparative immunotoxicity assays, as well as laying the groundwork for studies that can better define the development of the innate and adaptive immune responses of fathead minnow larvae.