The Role of Epigenetic Switches in Polyphenism Control: Implications from a Nematode Model for the Developmental Regulation of Alternative Phenotypes.

Polyphenisms, the capability of organisms to form two or more alternative phenotypes in response to environmental variation, are prevalent in nature. However, associated molecular mechanisms and potential general principles of polyphenisms among major organismal groups remain currently unknown. This review focuses on an emerging model system for developmental plasticity and polyphenism research, the nematode and explores mechanistic insight obtained through unbiased genetic, experimental and natural variation studies. Resulting findings identify a central role for epigenetic switches in the environmental control of alternative phenotypes and their micro-and macroevolution. Several features observed in are shared with insects and plants and might become general principles for the control of polyphenisms during development.