RRC ID 75740
Author Yano T, Abe G, Yokoyama H, Kawakami K, Tamura K.
Title Mechanism of pectoral fin outgrowth in zebrafish development.
Journal Development
Abstract Fins and limbs, which are considered to be homologous paired vertebrate appendages, have obvious morphological differences that arise during development. One major difference in their development is that the AER (apical ectodermal ridge), which organizes fin/limb development, transitions into a different, elongated organizing structure in the fin bud, the AF (apical fold). Although the role of AER in limb development has been clarified in many studies, little is known about the role of AF in fin development. Here, we investigated AF-driven morphogenesis in the pectoral fin of zebrafish. After the AER-AF transition at ∼36 hours post-fertilization, the AF was identifiable distal to the circumferential blood vessel of the fin bud. Moreover, the AF was divisible into two regions: the proximal AF (pAF) and the distal AF (dAF). Removing the AF caused the AER and a new AF to re-form. Interestingly, repeatedly removing the AF led to excessive elongation of the fin mesenchyme, suggesting that prolonged exposure to AER signals results in elongation of mesenchyme region for endoskeleton. Removal of the dAF affected outgrowth of the pAF region, suggesting that dAF signals act on the pAF. We also found that the elongation of the AF was caused by morphological changes in ectodermal cells. Our results suggest that the timing of the AER-AF transition mediates the differences between fins and limbs, and that the acquisition of a mechanism to maintain the AER was a crucial evolutionary step in the development of tetrapod limbs.
Volume 139(16)
Pages 2916-25
Published 2012-8-1
DOI 10.1242/dev.075572
PII dev.075572
PMID 22791899
MeSH Animal Fins / blood supply Animal Fins / embryology* Animals Animals, Genetically Modified Apolipoproteins E / genetics Apolipoproteins E / metabolism Base Sequence Biological Evolution Cell Shape DNA Primers / genetics Ectoderm / cytology Ectoderm / embryology Fibroblast Growth Factors / genetics Fibroblast Growth Factors / metabolism Gene Expression Regulation, Developmental Green Fluorescent Proteins / genetics Green Fluorescent Proteins / metabolism Homeodomain Proteins / genetics Homeodomain Proteins / metabolism Models, Biological Recombinant Proteins / genetics Recombinant Proteins / metabolism Transcription Factors / genetics Transcription Factors / metabolism Zebrafish / anatomy & histology Zebrafish / embryology* Zebrafish / genetics Zebrafish / metabolism Zebrafish Proteins / genetics Zebrafish Proteins / metabolism
IF 5.611
Zebrafish hspGFFDMC131A UAS:GFP