Assessment of lead toxicity on locomotion and growth in a nematode Caenorhabditis elegans

Abstract

Due to anthropogenic activities and natural abundance, lead exposure is a common phenomenon. Neurotoxic and genotoxic effects of lead are widely known. Recent studies have suggested that lead exposure can affect young generation and transfer to the progeny thus posing a great threat for future generation. The present study was focused on lead toxicity in terms of locomotion and growth of Caenorhabditis elegans (N2 wild type) at three sub-lethal doses (3µM, 15 µM and 30 µM) of Pb (NO3)2 for 24 hours (sub-chronic exposure). Caenorhabditis elegans is a nematode with an established eco- toxicity marker model organism, due to its short life cycle and ease to monitor. After lead  exposure, significant toxic manifestations were observed in locomotion of the nematode in terms of omega bends (+350% for 30 µM exposure dose, p<0.001), reversals (-26.98%, -49% and -66.35% for 3 µM, 15 µM and 30 µM exposure doses respectively, p<0.001), turn counts (-38.66%, -62.61% and -81.93% for 3 µM, 15 µM and 30 µM exposure doses respectively, p<0.001 ) and peristaltic speed alterations (+97.83%, +225.92% and +454.63% for 3 µM, 15 µM and 30 µM exposure doses respectively, p<0.001). Successive reduction in the body length at lower doses shows remarkable toxic alterations in nematodes. The obtained data may be useful to extrapolate the effects of lead exposure on humans, as many of the similar pathways and cellular processes affected by Pb in humans are also present in C. elegans.