Modification of the zone of polarizing activity signal by trypsin |
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| Authors: | Emily K Stefanov Jordan M Ferrage Nicholas F Parchim Christine E Lee Angela D Reginelli Mara Taché Rosalie A Anderson |
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| Institution: | 1. Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama,;2. School of Dentistry, Louisiana State University Health Sciences Center, New Orleans, Louisiana,;3. Medical School/Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas,;4. University of South Florida College of Medicine, Tampa, Florida,;5. Uptown Nephrology Clinic, New Orleans, Louisiana,;6. Austin Diagnostic Clinic, Pediatrics, Austin, Texas and;7. Department of Biological Sciences, Loyola University New Orleans, New Orleans, Louisiana, USA |
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| Abstract: | Patterning of the developing vertebrate limb along the anterior‐posterior axis is controlled by the zone of polarizing activity (ZPA) via the expression of Sonic hedgehog (Shh) and along the proximal‐distal axis by the apical ectodermal ridge (AER) through the production of fibroblast growth factors (FGFs). ZPA grafting, as well as ectopic application of SHH to the anterior chick limb bud, demonstrate that digit patterning is largely influenced by these secreted factors. Although signal transduction pathways have been well characterized for SHH and for FGFs, little is known of how these signals are regulated extracellularly in the limb. The present study shows that alteration of the extracellular environment through trypsin treatment can have profound effects on digit patterning. These effects appear to be mediated by the induction of Shh in host tissues and by ectopic AER formation, implicating the extracellular matrix in regulating the signaling activities of key patterning genes in the limb. |
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| Keywords: | apical ectodermal ridge patterning sonic hedgehog trypsin zone of polarizing activity |
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