title: Lmx-1b and Wnt-7a expression in axolotl limb during development and regeneration.
abstract: Axolotls (Ambystoma mexicanum) have the ability to regenerate amputated limbs throughout their life span. During limb regeneration as well as development, undifferentiated cells in the blastema acquire positional information to reproduce the original pattern along three cardinal limb axes: anteroposterior, proximodistal and dorsoventral. In the present study, we attempted to understand the molecular mechanism involved in patterning of axolotl limb development and regeneration along the dorsoventral (DV) axis. We cloned axolotl Lmx-1b and Wnt-7a, and investigated the expression pattern of these genes in developing and regenerating limbs. In axolotl, unlike in amniotes, Wnt-7a was expressed in a diffuse manner throughout both developing limb bud and regenerating limb blastema. Lmx-1b expression was observed at the dorsal mesenchyme in the developing and regenerating limbs. On the basis of the expression patterns of Lmx-1b and Wnt-7a, it was difficult to identify the interaction between these two genes as reported in amniotes in previous studies. Possibly, with regard to Lmx-1b expression, a Wnt-7a-independent mechanism may exist in axolotl limb development and regeneration.
authors.affiliation: Division of Anatomy II, Kanazawa Medical University, 1-1 Daigaku, Uchinada-machi, Kahoku-gun, 920-0293 Japan. imoort1@kanazawa-med.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimokawa
authors.forename: Satoru
authors.initials: S
authors.lastname: Yasutaka
authors.forename: Rieko
authors.initials: R
authors.lastname: Kominami
authors.forename: Harumichi
authors.initials: H
authors.lastname: Shinohara
mesh_terms: D000558:Ambystoma mexicanum / Q000378:metabolism*; D000595:Amino Acid Sequence; D000671:Amputation, Surgical; D000818:Animals; D005121:Extremities / Q000502:physiology* / Q000601:surgery; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D060850:LIM-Homeodomain Proteins / Q000378:metabolism*; D018878:Limb Buds / Q000378:metabolism*; D008969:Molecular Sequence Data; D012038:Regeneration / Q000502:physiology*; D051153:Wnt Proteins / Q000378:metabolism*
chemical_list: D060850:LIM-Homeodomain Proteins; D051153:Wnt Proteins