Molecular genetic analysis of the maize Suppressor-mutator element's epigenetic developmental regulatory mechanism
The genetic mechanism underlying the developmental regulation of the maize Suppressor-mutator element has been analyzed by molecular and genetic techniques. The element is subject to inactivation by a negative, epigenetic mechanism that results in the methylation of C residues in the vicinity of the element's transcription start site. Fully methylated elements are genetically and transcriptionally silent (cryptic), while hypomethylated elements are active. Partially methylated elements, designated programable, exhibit a variety of developmental expression programs. The element encodes a positive regulatory gene product which activates element expression and promotes reprograming of the element by interfering with methylation of the element's 5′ end.Key words: maize transposable element, Suppressor-mutator element, developmental regulation.