Abstract:
Caenorhabditis elegans has been used as a model organism in many areas of research
over the last few decades. This research investigated stress related changes in C.elegans
following exposure to different components of B.anthracis and varying dosages of lead
acetate. Metabolites of purine, tyrosine and tryptophan pathways of C.elegans were
measured using high profile liquid chromatography coupled with electrochemical
detection. Perturbations in metabolites of these pathways in C.elegans were measured
and compared to the metabolites of the untreated. C.elegans cultures grown under axenic
and monoxenic conditions responded differently to the same stressors. The results from
this research support the hypothesis that a relationship exists between the initial stress
response and the subsequent changes in the metabolic constituents of purine, tyrosine
and/or tryptophan pathways of C.elegans.
The exposure of axenic mixed cultures of C.elegans to a Bacillus anthracis threetoxin
combination resulted in an acute response showing perturbations in purine, tyrosine
and tryptophan pathways. Increasing the concentration of lead affected growth in axenic
young, reproductive processes in axenic middle aged after 1.5 days of exposure whereas
the adult C.elegans lysed. Perturbations in analytes of purine, tyrosine and tryptophan, as
well as unknown analytes specific to the life stage and dosage of lead treatment, were
observed. Axenic and monoxenic C.elegans demonstrated time and dose-dependent
responses to lead exposure. Axenic C.elegans cultures responded to biological stressors
and lead acetate more rapidly than monoxenic cultures, suggesting that axenic cultures
could provide a superior model system for measuring acute stress responses.
