title: Proximodistal identity during vertebrate limb regeneration is regulated by Meis homeodomain proteins.
abstract: The mechanisms by which cells obtain instructions to precisely re-create the missing parts of an organ remain an unresolved question in regenerative biology. Urodele limb regeneration is a powerful model in which to study these mechanisms. Following limb amputation, blastema cells interpret the proximal-most positional identity in the stump to reproduce missing parts faithfully. Classical experiments showed the ability of retinoic acid (RA) to proximalize blastema positional values. Meis homeobox genes are involved in RA-dependent specification of proximal cell identity during limb development. To understand the molecular basis for specifying proximal positional identities during regeneration, we isolated the axolotl Meis homeobox family. Axolotl Meis genes are RA-regulated during both regeneration and embryonic limb development. During limb regeneration, Meis overexpression relocates distal blastema cells to more proximal locations, whereas Meis knockdown inhibits RA proximalization of limb blastemas. Meis genes are thus crucial targets of RA proximalizing activity on blastema cells.
authors.affiliation: Departamento de Inmunología y Oncología, Centro Nacional de Biotecnología/CSIC, Campus de Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Nadia
authors.initials: N
authors.lastname: Mercader
authors.forename: Elly M
authors.initials: EM
authors.lastname: Tanaka
authors.forename: Miguel
authors.initials: M
authors.lastname: Torres
mesh_terms: D000558:Ambystoma mexicanum / Q000502:physiology*; D000671:Amputation, Surgical; D000818:Animals; D015153:Blotting, Western; D003001:Cloning, Molecular; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics; D018274:Electroporation; D005552:Forelimb / Q000502:physiology*; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D000075064:Myeloid Ecotropic Viral Integration Site 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D000075062:Pre-B-Cell Leukemia Transcription Factor 1; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012038:Regeneration / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014212:Tretinoin / Q000378:metabolism
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D000075064:Myeloid Ecotropic Viral Integration Site 1 Protein; D009363:Neoplasm Proteins; D000075062:Pre-B-Cell Leukemia Transcription Factor 1; D011518:Proto-Oncogene Proteins; C083400:PBX1 protein, human; D014212:Tretinoin