Chapter category: Adhesion Molecules
Chromatin and the Control of Hox Gene Expression
HOX Gene Expression
Edited by: Spyros PapageorgiouISBN: 978-0-387-68989-0
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Antero-posterior patterning of the animal embryo is governed in part by the highly conserved Hox genes. In most animals studied to date, Hox genes are assembled within one or more clusters. The thirty-nine Hox genes of mice and humans are organized into four clusters, each located on a different chromosome. There are thirteen possible gene positions in each cluster, although none of the clusters retains all thirteen members (Fig. 1). Hox genes occupying the same relative position between clusters are termed paralogs, sharing high sequence identity and functional redundancy. Because all genes are transcribed in the same direction, one can assign a 3\' and a 5\' end to a cluster. Consistent with their key role in embryonic patterning, Hox gene expression is tightly regulated at the transcriptional level, and the desire to define the mechanisms controlling this expression has driven many research programs. Consequent to shifts in our understanding of transcriptional regulation generally, these programs have broadened to include not only the identification of sequence-specific transcription factors and the cis-elements to which they bind, but also the role of chromatin modification and remodeling. A detailed introduction to the mechanisms modulating chromatin structure and function is beyond the scope of this discussion, and readers are directed to numerous reviews on the subject.
Additional chapters from this book:
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Chromatin and the Control of Hox Gene Expression
Antero-posterior patterning of the animal embryo is governed in part by the highly conserved Hox genes. In most animals studied to date, Hox genes are assembled within one or more clusters. The thirty...
