title: Progressive specification rather than intercalation of segments during limb regeneration.
abstract: An amputated salamander limb regenerates the correct number of segments. Models explaining limb regeneration were largely distinct from those for limb development, despite the presence of common patterning molecules. Intercalation has been an important concept to explain salamander limb regeneration, but clear evidence supporting or refuting this model was lacking. In the intercalation model, the first blastema cells acquire fingertip identity, creating a gap in positional identity that triggers regeneration of the intervening region from the stump. We used HOXA protein analysis and transplantation assays to show that axolotl limb blastema cells acquire positional identity in a proximal-to-distal sequence. Therefore, intercalation is not the primary mechanism for segment formation during limb regeneration in this animal. Patterning in development and regeneration uses similar mechanisms.
authors: Deutsche Forschungsgemeinschaft (DFG)-Center for Regenerative Therapies Dresden, Technische Universität Dresden, Germany.
authors: Kathleen
authors: K
authors: Roensch
authors: Akira
authors: A
authors: Tazaki
authors: Osvaldo
authors: O
authors: Chara
authors: Elly M
authors: EM
authors: Tanaka
mesh_terms: D000558:Ambystoma mexicanum; D000818:Animals; D019521:Body Patterning; D005121:Extremities / Q000033:anatomy & histology / Q000502:physiology*; D018398:Homeodomain Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D012038:Regeneration
chemical_list: D018398:Homeodomain Proteins; C099959:homeobox protein HOXA13; C097899:homeobox protein HOXA9