Planarians as a model system for in vivo teratogenesis studies

Abstract

Planarians are free-living flatworms whose organ systems are capable of carrying out complex metabolic functions similar to those of mammals. The biological similarity of planarians to mammals, and the ease and low cost of culturing planarians in the laboratory, makes them a good in vivo animal for screening and mechanistic studies of acute, chronic, neurobehavioral, reproductive, and developmental toxicology. Because only undifferentiated totipotent stem cells, i.e., neoblasts, are capable of mitosis and differentiation in planarians, all abnormal growths, including tumors, originate from this target cell. This review evaluates planarians for use in developmental toxicology as a screening bioassay for compounds and mixtures, and for mechanistic studies.