In vivo methods to analyze chromatin structure.

A groundswell of interest in chromatin structure and its role in regulating the function of DNA in transcription, replication, recombination and repair has developed in the past decade. Fueled by genetic observations of effects of histone mutations on transcription and identification of genes whose products must alter chromatin structure as they affect gene activity, this subject leapt to the forefront in the past two years with the correlation of certain transcription factors with enzymes that post-translationally modify histones and are presumed to alter chromatin structure thereby. Surprisingly few experimental reports have actually addressed chromatin structure. In part, this may be related to the technical difficulties of traditional approaches to structure inference. Methods have become available recently for assessment of various aspects of chromatin structure in vivo. Study in intact cells may limit potential problems resulting from loss of components or rearrangement of structures and simplify analysis by eliminating the need for isolation of organelles.