UC Riverside

Nematode bioassays form a useful approach to evaluate the toxicity of chemical compounds of interest. Such evaluations are important for confirming a compound's effectiveness and the duration thereof. In medicine, it is essential to know the minimally effective dose of a drug compound to supply so that overdosing may be prevented. In agriculture, nematode bioassays are crucial tools for conducting efficacy and safety assessments before any soil application of novel chemicals, thereby avoiding the build-up of hazardous waste. Nematodes are known as bioindicators of soil health status and can be very sensitive to soil modifications. Changes in soil composition and structure will affect the types and species of nematodes that inhabit a patch of soil, making them useful indicators for testing the effects of distinct compounds. Bioassays allow observation of changes in nematode behavior as well as changes in their mobility and mortality.Caenorhabditis elegans, the model nematode, has been used to observe its responses to exposure to different compounds. Other bioassays have employed plant-parasitic nematodes such as stubby root nematodes (e.g.,TrichodorusandParatrichodorusspp.) and root-knot nematodes (Meloidogynespp.). In vitroassays can be used to perform rapid analyses in the laboratory. These tests can help reveal the molecular and cellular mechanisms of a compound’s toxicity through changes in nematode behavior, mobility, and death when working with juveniles. When working with adult nematodes, effects on nematode egg hatch can also be analyzed.