Histone acetylation influences both gene expression and development of Xenopus laevis

Abstract

We examine the potential role of histonehyperacetylation in gene activation during Xenopus development using Trichostatin A, (TSA), a specific inhibitor of histone deacetylase. We find that TSA is very effective in inducing both core histone hyperacetylation and histone H1° gene expression in aXenopus somatic cell line. In contrast, TSA does notinduce histone hyperacetylation or histone H1° transcription in Xenopusoocytes. Histone hyperacetylation is developmentally regulated during Xenopusembryogenesis; hyperacetylated histones first accumulate early in gastrulation. The capacity of TSA to induce histone H1° gene expression correlateswith the induction of histone hyperacetylation. Concentrationsof TSA sufficient to induce histone hyperacetylation in Xenopus embryos delay gastrulation andcause diminished midtrunk and posterior formation, suggesting defects in mesoderm formation. Although the constitutive hyperacetylation of the histonesdoesnot prevent either the cell division or differentiation sufficient for early morphogenesis it has a rolein establishing stable states of differential gene activity during gastrulation. © 1994 by Academic Press, Inc.