Ref ID : 2165
Eve G. Stringham and E.Peter M. Candido; Transgenic hsp16-lacZ strains of the soil nematode Chaenorhabditis elegans as Biological monitors of environmental stress. Environmental Toxicology & Chemistry 13(8):1211-1220, 1994
Reprint
In File
Notes
Caenorhabditis elegans is a small, free-living hermaphroditic nematode that is widely used for the investigation of basic biological phenomena at the genetic and molecular levels. The hsp 16 genes in this system encode a family of stress-inducible 16-kDa proteins. Stable transgenic nematode lines were derived that carry fusions of the hsp 16 genes to the Escherichia coli lacZ reporter gene. These transgenic strains express high levels of beta-galactosidase in the nucleus, in response to a heat shock or to a variety of chemical stressors. Agents tested to data that induce the stress response in these animals include Cd2+, Cu2+, Hg2+, Pb2+, Zn2+, AsO2-, and the herbicide paraquat. Some of these agents yield distinct tissue patterns of stress induction (e.g., Pb2+ in the posterior pharynx, Cd2+ throughout the pharynx, Hg2+ in intestine), suggesting that classification of stress agents in complex mixtures may be a useful feature of this biomonitoring system. Using a soluble beta-galactosidase substrate, an assay was developed that allows the magnitude of the stress response to be measured. Stress reporter gene induction always occurred below the LC50 of the test substance, suggesting that this assay is a more sensitive and rapid indicator of stress than current LC50 assays using Chaenorhabditis elegans.