Somatic linker histones cause loss of mesodermal competence in Xenopus

摘要: In Xenopus, cells from the animal hemisphere are competent to form mesodermal tissues morula through blastula stage1. Loss of competence at early gastrula is programmed cell-autonomously, and occurs even in single appropriate stage2. To determine mechanism by which this occurs, we have been investigating a concomitant, global change expression H1 linker histone subtypes. histones usually considered be general repressors transcription3, but Xenopus they increasingly thought selective functions transcriptional regulation4,5,6. eggs embryos stages before midblastula transition7 deficient protein, contain an oocyte-specific variant called B4 or H1M. After transition, progressively substituted three somatic variants, replacement complete neurula8,9. Here report that accumulation protein rate limiting for loss competence. This involves silencing regulatory genes required differentiation pathways, like muscle, somatic, not maternal, protein.