C. Elegans Chemotaxis and Reproduction Following Environmental Exposure

Abstract

The free-living nematode Caenorhabditis elegans (C. elegans) is a well established biological model. Chemotaxis is an important behavior in enabling it to locate food sources such as E.coli. This study evaluates the chemotaxis of C.elegans to food following exposure to Moxidectin (Cydectin), Black Seed Oil, non-fat milk, or colostrum. A ring of bacteria (food) on nematode growth agar medium served as attractive signals to encourage C. elegans to move. Nematodes were placed in the center of the agar plate in Moxidectin, Black seed oil, colostrum or non-fat milk. Over the three day life cycle the reproduction (number of worms), movement (yes or no) and chemotaxis (number migrating to the ring of bacteria through the chemical) was recorded. Exposure to different chemicals differentially affected the total number of worms, movement and chemotaxis. Moxidectin and black seed oil inhibited migration and reproduction at the concentrations tested. Both colostrum and non-fat milk increased migration and reproduction. Caenorhabditis elegans is a sensitive multi-cellular bio and chemosensor. The bacterial ring assay is a very useful in vitro approach for evaluation of the effect of chemical exposure on chemotactic behavior and reproduction. Thus, this model can be used to better understand the molecular basis of the response to environmental exposure and for identifying molecular targets or biochemical pathways involved.