Cyclic nucleotide exudation by nematodes and the effects on nematode growth, development and longevity
The levels of the cyclic nucleotides, cAMP and cGMP, in the medium of aging mass cultures of Panagrellus redivivus were determined, respectively, by a protein binding assay and a radio-immunoassay. The amount of cGMP increased as the mass cultures aged while the amount of cAMP remained stable. Since premature death and an inhibition of development have been observed in aging mass cultures, investigators have speculated that a build-up of excretory products in the medium might be toxic to the nematodes and cause abnormal development.
To examine this possibility, small cultures containing fixed numbers of the nematode Caenorhabditis elegans were exposed to levels of cGMP analagous to the levels found in aging mass cultures of P. redivivus. Significant increases in growth and longevity occurred with no effect on fecundity, timing or the duration of the reproductive period. It appears then that cGMP is not responsible for the toxic effects observed in mass culture and, in fact, cGMP apparently enhances nematode longevity at concentrations which do not alter normal development.
KeywordsNucleotide Toxic Effect Binding Assay Normal Development Caenorhabditis Elegans
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