蝾螈肢体发育和再生过程中Lmx-1b和Wnt-7a的表达
Lmx-1b and Wnt-7a expression in axolotl limb during development and regeneration.
作者信息
Shimokawa Takashi, Yasutaka Satoru, Kominami Rieko, Shinohara Harumichi
机构信息
Division of Anatomy II, Kanazawa Medical University, 1-1 Daigaku, Uchinada-machi, Kahoku-gun, 920-0293 Japan.
出版信息
Okajimas Folia Anat Jpn. 2013;89(4):119-24. doi: 10.2535/ofaj.89.119.
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.
美西螈(墨西哥钝口螈)在其整个生命周期中都具有再生被截断肢体的能力。在肢体再生以及发育过程中,芽基中的未分化细胞获取位置信息,以沿着肢体的三个主要轴(前后轴、近端-远端轴和背腹轴)重现原始模式。在本研究中,我们试图了解美西螈肢体发育和沿背腹(DV)轴再生过程中模式形成所涉及的分子机制。我们克隆了美西螈Lmx-1b和Wnt-7a,并研究了这些基因在发育中和再生肢体中的表达模式。在美西螈中,与羊膜动物不同,Wnt-7a在整个发育中的肢芽和再生肢体芽基中呈弥漫性表达。在发育中和再生肢体的背侧间充质中观察到Lmx-1b表达。基于Lmx-1b和Wnt-7a的表达模式,很难像先前研究在羊膜动物中报道的那样确定这两个基因之间的相互作用。可能在美西螈肢体发育和再生过程中,关于Lmx-1b表达可能存在一种不依赖Wnt-7a的机制。