Nuclear re-organisation of the Hoxb complex during mouse embryonic development.

摘要: The spatial and temporal co-linear expression of Hox genes during development is an exquisite example programmed gene expression. precise mechanisms underpinning this are not known. Analysis Hoxb chromatin structure nuclear organisation, during the differentiation of murine ES cells, has lent support to idea that there a progressive `opening9 chromatin propagated through clusters from 3′ to 5′, which contributes sequential activation gene expression. Here, we show similar events occur in vivo at least two stages development. first changes nuclear organisation were detected gastrulation the Hoxb1 -expressing posterior primitive streak region: was decondensed locus looped out its chromosome territory, contrast non-expressing Hoxb9 , which remained within chromosome territory. At E9.5, when differential Hox expression along anteroposterior axis being established, found concomitant organisation Hoxb. organisation differed between regions neural tube had never expressed [rhombomeres (r) 1 2], strongly expressed but not b9 (r4), downregulated (r5), but (spinal cord), both genes (tail bud). We conclude decondensation and nuclear re-organisation regulated different parts developing embryo, developmental stages. developing neural coherent with In early development coupled expression, but does anticipate it.