Injection of antibodies into the nucleus of amphibian oocytes : an experimental means of interfering with gene expression in the living cell

Abstract

ABSTRACT The chromatin constituents associated with transcriptionally active genes can be studied by a variety of experimental approaches. Most of the methods used involve the isolation of active chromatin fractions followed by biochemical analysis, or are based on in vitro assays with the ultimate goal of reconstituting faithful transcription by adding purified and defined components to the transcriptional machinery (for reviews see Mathis, Oudet & Chambon, 1980; Rose, Stetler & Jacob, 1983a; Beroldingen et al. 1984; Reeves, 1984; Dynan & Tjian, 1985; Sentenac, 1985). Since these approaches require isolation of chromatin or of individual components therefrom, possible structural rearrangements or selective losses of certain constituents cannot a priori be excluded. Therefore it often remains questionable whether the results obtained in vitro reflect the actual situation in the living cell.