| The Midgut Epithelium of Aquatic Arthropods: A Critical Target Organ
in Environmental Toxicology Barry J. Beaty, Ryan S. Mackie, Kimberly S. Mattingly, Jonathan
O. Carlson, and Alfredo Rayms-Keller Arthropod-borne and Infectious Diseases Laboratory and the Center
for Environmental Toxicology and Technology, Colorado State University,
Fort Collins, Colorado, USA
Abstract
The midgut epithelium of aquatic arthropods is emerging as an important and toxicologically relevant organ system for monitoring environmental pollution. The peritrophic matrix of aquatic arthropods, which is secreted by the midgut epithelium cells, is perturbed by copper or cadmium. Molecular biological studies have identified and characterized two midgut genes induced by heavy metals in the midgut epithelium. Many other metal-responsive genes (MRGs) await characterization. One of the MRGs codes for an intestinal mucin, which is critical for protecting the midgut from toxins and pathogens. Another codes for a tubulin gene, which is critical for structure and function of the midgut epithelial cells. Perturbation of expression of either gene could condition aquatic arthropod survivorship. Induction of these MRGs is a more sensitive and rapid indicator of heavy-metal pollution than biological assays. Characterization of genes induced by pollutants could provide mechanistic understanding of fundamental cellular responses to pollutants and insight into determinants of aquatic arthropod population genetic structure and survivorship in nature. Key words: aquatic arthropods, heavy metals, metal-responsive genes, midgut epithelium, mucin, tubulin. Environ Health Perspect 110(suppl 6) :911-914 (2002) . http://ehpnet1.niehs.nih.gov/docs/2002/suppl-6/911-914beaty/abstract.html
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