Real-time PCR array to study the effects of chemicals on the growth hormone/insulin-like growth factors (GH/IGFs) axis of zebrafish embryos/larvae

Growth hormone/insulin-like growth factors (GH/IGFs) axis PCR array of zebrafish (Danio rerio) larvae was developed based on the quantification of mRNA expressions of 19 genes that were confirmed to play vital roles in the regulation of fish growth. Zebrafish embryos were exposed to each of four concentrations of the six representative chemicals, bisphenol A (BPA), perfluorooctane sulfonates (PFOS), tris (1,3-dichloroisopropyl) phosphate (TDCIPP), cadmium chloride (CdCl2), mercury (II) chloride (HgCl2) and lead (II) acetate (PbAc) from 2 h post fertilization (hpf) to 96 hpf. Developmental endpoints and transcriptional profiles of the genes involved in GH/IGFs axis of zebrafish larvae were examined at 96 hpf. Body length of zebrfish larvae was found to be a more susceptible endpoint in zebrafish embryo toxicity test than other endpoints, including survival rate, hatching rate, malformation incidence and heart rate after exposure to each of those representative chemicals selected. Perturbation of mRNA expressions of GH/IGF axis genes accompanied by decreased body length indicated that indicated that the growth inhibition observed might be attributed to the dysregulation of GH/IGFs axis. Therefore, GH/IGF axis PCR array of zebrafish larvae could be used to evaluate the effects of chemicals on GH/IGF endocrine system.