AnEvaluation of Lead (Pb) Toxicity in Developing Zebrafish(Daniorerio) Embryos

Lead (Pb) toxicity is known to cause an array of defects including developmental, cellular and neurological damage. Although numerous studies have attempted to characterize the mechanism underlying lead toxicity, the exact molecular targets remain unclear.Additionally, there is a discrepancy among different studies regarding the concentrations of lead at which developmental defects arise. The present study was conducted to characterize the developmental malformations induced in Zebrafish embryos following a brief exposure to lead. The study also attempted to identify changes in protein profiles in Zebrafish embryos following lead exposure to identify putative molecular targets of lead toxicity. Embryos were treated with varying concentrations of lead (100ppb,500ppb, 1000ppb) at 5 hours post fertilization (hpf) until 24hpf. Morhological observations of various developmental parameters such as embryo viability, hatching rate, heart beats, eye diameter, straightening of body axis were carried out at 48hpf, 72hpf and 96hpf. Proteins extracted from embryos at these stages were subjected to SDS-PAGE and silver staining to observe changes in protein band patterns following lead treatment. An increase in hatching rate, heart beats and eye diameter was notedat 48hpf following treatment. Lead treatment was also seen to induce subtle changes in electrophoretic protein band patterns as compared to controls.