The chicken polydactyly (Po) locus causes allelic imbalance and ectopic expression of Shh during limb development

Authors

  • Ian C. Dunn,

    1. Division of Genetics and Genomics, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, United Kingdom
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  • I. Robert Paton,

    1. Division of Genetics and Genomics, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, United Kingdom
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  • Allyson K. Clelland,

    1. Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
    Current affiliation:
    1. School of Biology, University of St Andrews, Bute Medical Buildings, St Andrews, Fife KY16 9TS, UK
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  • Sujith Sebastian,

    1. Division of Genetics and Genomics, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, United Kingdom
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  • Edward J. Johnson,

    1. Division of Developmental Biology, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom
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  • Lynn McTeir,

    1. Division of Developmental Biology, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom
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  • Dawn Windsor,

    1. Division of Genetics and Genomics, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, United Kingdom
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  • Adrian Sherman,

    1. Division of Developmental Biology, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom
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  • Helen Sang,

    1. Division of Developmental Biology, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom
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  • Dave W. Burt,

    1. Division of Genetics and Genomics, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, United Kingdom
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  • Cheryll Tickle,

    1. Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
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  • Megan G. Davey

    Corresponding author
    1. Division of Developmental Biology, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Midlothian, United Kingdom
    • Division of Developmental Biology, The Roslin Institute and Royal Dick School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian EH25 9RG, UK
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Abstract

Point mutations in the intronic ZRS region of Lmbr1, a limb specific cis-regulatory element of Sonic hedgehog (Shh), are associated with polydactyly in humans, cats, and mice. We and others have recently mapped the dominant preaxial polydactyly (Po) locus in Silkie chickens to a single nucleotide polymorphism (SNP) in the ZRS region. Using polymorphisms in the chicken Shh sequence, we confirm that the ZRS region directly regulates Shh expression in the developing limb causing ectopic Shh expression in the anterior leg, prolonged Shh expression in the posterior limb, and allelic imbalance between wt and Slk Shh alleles in heterozygote limbs. Using Silkie legs, we have explored the consequences of increased Shh expression in the posterior leg on the patterning of the toes, and the induction of preaxial polydactyly. Developmental Dynamics 240:1163–1172, 2011. © 2011 Wiley-Liss, Inc.

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