title: Holmgren's principle of delamination during fin skeletogenesis.
abstract: During fin morphogenesis, several mesenchyme condensations occur to give rise to the dermal skeleton. Although each of them seems to create distinctive and unique structures, they all follow the premises of the same morphogenetic principle. Holmgren's principle of delamination was first proposed to describe the morphogenesis of skeletal elements of the cranium, but Jarvik extended it to the development of the fin exoskeleton. Since then, some cellular or molecular explanations, such as the "flypaper" model (Thorogood et al.), or the evolutionary description by Moss, have tried to clarify this topic. In this article, we review new data from zebrafish studies to meet these criteria described by Holmgren and other authors. The variety of cell lineages involved in these skeletogenic condensations sheds light on an open discussion of the contributions of mesoderm- versus neural crest-derived cell lineages to the development of the head and trunk skeleton. Moreover, we discuss emerging molecular studies that are disclosing conserved regulatory mechanisms for dermal skeletogenesis and similarities during fin development and regeneration, which may have important implications in the potential use of the zebrafish fin as a model for regenerative medicine.
authors.affiliation: Laboratory of Bioengineering and Tissue Regeneration (LABRET), Department of Cell Biology, Genetics and Physiology, Biomedical Research Institute of Málaga (IBIMA), Faculty of Sciences, University of Málaga, 29071 Málaga, Spain; Department of Orthopedic Surgery, University of California, Los Angeles, CA 90095, USA; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 29071 Málaga, Spain. Electronic address: iduranjimenez@mednet.ucla.edu.
authors.forename: I
authors.initials: I
authors.lastname: Duran
authors.affiliation: Laboratory of Bioengineering and Tissue Regeneration (LABRET), Department of Cell Biology, Genetics and Physiology, Biomedical Research Institute of Málaga (IBIMA), Faculty of Sciences, University of Málaga, 29071 Málaga, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 29071 Málaga, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Ruiz-Sánchez
authors.affiliation: Laboratory of Bioengineering and Tissue Regeneration (LABRET), Department of Cell Biology, Genetics and Physiology, Biomedical Research Institute of Málaga (IBIMA), Faculty of Sciences, University of Málaga, 29071 Málaga, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 29071 Málaga, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Santamaría
authors.affiliation: Laboratory of Bioengineering and Tissue Regeneration (LABRET), Department of Cell Biology, Genetics and Physiology, Biomedical Research Institute of Málaga (IBIMA), Faculty of Sciences, University of Málaga, 29071 Málaga, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 29071 Málaga, Spain. Electronic address: beffa@uma.es.
authors.forename: M
authors.initials: M
authors.lastname: Marí-Beffa
mesh_terms: D058500:Animal Fins / Q000166:cytology / Q000254:growth & development*; D000818:Animals; D006801:Humans; D008648:Mesoderm / Q000166:cytology / Q000502:physiology; D023421:Models, Animal; D009024:Morphogenesis; D012038:Regeneration; D012886:Skull / Q000166:cytology / Q000254:growth & development
keywords: Dermal skeleton; Holmgren's principle; Mesenchyme condensation; Mesoderm; Neural crest