The adr-2 Mutant Strain of C. elegans and the Effect of Gold Nanoparticles on Life Span and Induction of Immune Responses

Abstract

Abstract Nanoparticles (NP) are widely used for domestic, industrial and medical applications. However, because of their nano-size they can easily penetrate cellular membranes, causing increased damage to the mitochondrial and genomic DNA. NPs also were reported to induce inflammation, cell apoptosis and oxidative stress. In this research, the effect of gold NPs on growth, reproduction, fecundity, life span as well as induction of immune responses in Caenorhabditis elegans (C. elegans) are studied. The nematode has proven to be the best model to study effects difficult to explore in humans. The adr-2 mutant C. elegans is highly susceptible to environmental toxicity and offer sensitive bioassays to study the impacts of gold NPs on the worm. Two groups of adr-2 mutant C. elegans were grown. One group was exposed to gold NPs and the responses were analyzed and compared to the control group without nanoparticles. The two groups of C. elegans were observed over 2 months, thrashes were counted and the experiment was repeated several times. Findings showed that the thrash count for mutant strains decreases. Thus, at 0 minutes the thrash count was 55, reached 45 at two minutes, and decreased to 30 at four minutes. The other environmental contributors to this effect are under evaluation. The preliminary results showed that both groups had no visible changes. Nematodes were imaged using confocal differential interference contrast (DIC) microscopy. Several different pathways (p38 MAPK (PMK-1) and insulin like receptors (DAF-2)) could be activated to contribute to stress resistance to the NPs. Mutant strains of C. elegans for these receptors need to be tested to get a better understanding of the effect of the gold NPs on the immune responses.