Pbx homeodomain proteins: TALEnted regulators of limb patterning and outgrowth

Authors

  • Terence D. Capellini,

    1. Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, New York
    Current affiliation:
    1. Department of Developmental Biology, Stanford University School of Medicine, Beckman Center B300, 279 Campus Drive, Stanford, CA 94305
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  • Vincenzo Zappavigna,

    1. Department of Biology, University of Modena and Reggio-Emilia, Modena, Italy
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  • Licia Selleri

    Corresponding author
    1. Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, New York
    • Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021
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Abstract

Limb development has long provided an excellent model for understanding the genetic principles driving embryogenesis. Studies utilizing chick and mouse have led to new insights into limb patterning and morphogenesis. Recent research has centered on the regulatory networks underlying limb development. Here, we discuss the hierarchical, overlapping, and iterative roles of Pbx family members in appendicular development that have emerged from genetic analyses in the mouse. Pbx genes are essential in determining limb bud positioning, early bud formation, limb axes establishment and coordination, and patterning and morphogenesis of most elements of the limb and girdle. Pbx proteins directly regulate critical effectors of limb and girdle development, including morphogen-encoding genes like Shh in limb posterior mesoderm, and transcription factor-encoding genes like Alx1 in pre-scapular domains. Interestingly, at least in limb buds, Pbx appear to act not only as Hox cofactors, but also in the upstream control of 5′ HoxA/D gene expression. Developmental Dynamics 240:1063–1086, 2011. © 2011 Wiley-Liss, Inc.

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