Using the Drosophila melanogaster to Assessment Carcinogenic Agents through the Test for Detection of Epithelial Tumor Clones (Warts)

Abstract

Genetic toxicology testing has initially concentrated on induction of gene mutations and chromosome aberrations because these genetic changes are considered of great importance for it induces heritable diseases as well as the initiation of cancer. The classical studies on the genetic events underlying the development of tumors proved the importance of phenomenon termed “loss of heterozygosity”. Gene conversion and, mitotic recombination are potent mechanisms leading to loss of heterozigosity. The most important is that the step of induced loss of heterozygosity may be an early or a late step in carcinogenesis. During early embryonic development, groups of cells (imaginal discs) are set apart. They proliferate mitotically during the larval development until they differentiate during metamorphosis into structures of the body of the adult fly (eyes, wings). If a genetic alteration occurs in one of these imaginal disc cells, this alteration will be present in all the descendant cells and will form a clone of mutant cells. The wts (warts) gene was identified based on its ability to act as a tumor suppressor in Drosophila. Deletion, recombination of this gene leads to the formation of cells clones that are rounded and greatly overgrown, and literally generate “warts” (tumors) on their body. This system test will be a useful additional genetic endpoint in toxicological studies in general, as well as in studies to evaluate carcinogenic agents.