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New insights into mechanisms governing interdigital cell death during hindlimb development of the chick and duck
Author(s) -
Hasso Sean M,
Black Laura E,
Fallon John F
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a204
Subject(s) - fgf8 , mesenchyme , biology , fibroblast growth factor , bone morphogenetic protein , programmed cell death , limb development , microbiology and biotechnology , anatomy , gene , receptor , genetics , apoptosis , embryo
Regression of the autopod interdigital (ID) tissue, webbing between the fingers and toes, is accompanied by programmed cell death (PCD). We are testing the current hypothesis that ID PCD requires both Bone Morphogenic Protein (BMP) and Fibroblast growth factor (Fgf) signaling. In the chick, BMPs are expressed by the interdigital mesenchyme, whereas Fgf8 is expressed in the apical epithelium. Notably, PCD is first observed in the proximal ID, which is outside the influence of Fgf8. Gremlin , a BMP antagonist thought to inhibit ID PCD in the duck and bat, is also expressed in this proximal region. The molecular profile of these ID cells led us to explore other mechanisms for proximal PCD and how the death of these cells differed from what is seen in the distal ID at later stages. During interdigital regression, we observe coincident changes in the ID vascular network. We are exploring the notion that local regression of the limb bud vasculature is a necessary requirement for ID cell death. Using chick and duck, we report differences in gene expressions believed to be involved in facilitating or preventing PCD. Finally, we test whether the ID vasculature plays a functional role in PCD by experimentally inhibiting vascular regression. We conclude that BMP and Fgf signaling are not sufficient to explain ID regression. Funding by NIH‐NICHD (J.F.F.) and the Hilldale Undergraduate Research Fellowship of U.WI (L.E.B.)