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Presenting Author(s) Sarah Maas
Abstract Title The chicken oligozeugodactyly (ozd) mutant contains a deletion within Lmbr1 intron 5.
Full author List Sarah A. Maas and F.J.Verbeek
Text of abstract Sonic Hedgehog (SHH) is a secreted factor necessary for development of many organs throughout the vertebrate embryo. In the developing limb, Shh is expressed at the posterior margin of the limb bud by a small group of mesenchymal cells and is required for proper patterning of the limb skeleton along the anteroposterior (A/P) axis. The chicken mutant oligozeugodactyly (ozd) has normal Shh expression throughout the embryo except in the developing limbs, where Shh expression is absent. This limb specific absence of Shh leads to the loss of specific bones in both the wing and leg. Humans affected with acheiropodia (ACHP) have limbs that closely resemble ozd limbs, and the ACHP mutation has been mapped to a deletion of exon 4 and several kilobases of introns 3 and 4 of the LMBR1 gene. Although ozd mutant chickens are phenotypically similar to ACHP affected individuals, we have previously shown that ozd mutant chickens do not contain mutations within the region deleted in ACHP. Recent data from others suggests that a long-range limb specific Shh cis-acting regulator is contained within a highly conserved region of LMBR1 intron 5. We have analyzed this region in the chick and find that the chicken ozd mutant contains a deletion of 1654 bases within intron 5 of chick Lmbr1, deleting most of this highly conserved region and several hundred base pairs of nonconserved intronic sequence. Additional experiments are in progress to further define the importance of this region for limb specific Shh regulation during vertebrate limb development.
Which session is your work most relevant to: Limb patterning