Matsuda H, Yokoyama H, Endo T, Tamura K, Ide H
Biological Institute, Graduate School of Science, Tohoku University, Aoba-yama Aoba-ku, Sendai, 980-8578, Japan.
Dev Biol. 2001 Jan 15;229(2):351-62. doi: 10.1006/dbio.2000.9973.
The results of recent studies have supported the idea that the ability to organize the formation of axes such as the anteroposterior and proximodistal axes corresponds to limb regeneration ability in Xenopus. In this study, we investigated the mechanism by which the dorsoventral (D-V) axis of regenerating Xenopus limbs is established and the relationships between D-V patterning and regenerative ability. Transplantation experiments were performed to study which epidermis or mesenchyme is responsible for the D-V patterning in regenerating limbs. Naked mesenchyme of a donor limb was rotated and implanted on a host opposite-side limb stump to make a reversed recombination about the D-V axis. The resultant regenerates had a normal-looking D-V pattern, including Lmx-1 expression, muscle pattern, and joints, in stage 52 recombinants and a reversed D-V pattern in stage 55 recombinants. Further experiments in recombination at stage 52 and stage 55 showed that the epidermal signal is responsible for producing the D-V pattern in the regenerating blastema. These results, together with the finding that Lmx-1 expression is absent in the froglet forelimb blastema, suggest that D-V axis formation is a key step in understanding the loss of regenerative ability.
近期研究结果支持了这样一种观点，即组织前后轴和近远轴等轴形成的能力与非洲爪蟾的肢体再生能力相关。在本研究中，我们探究了非洲爪蟾再生肢体背腹（D-V）轴建立的机制以及D-V模式与再生能力之间的关系。进行了移植实验，以研究再生肢体中负责D-V模式形成的是哪种表皮或间充质。将供体肢体的裸间充质旋转并植入宿主对侧肢体残端，以形成关于D-V轴的反向重组。在52期重组体中，所得再生肢体具有外观正常的D-V模式，包括Lmx-1表达、肌肉模式和关节，而在55期重组体中则具有反向的D-V模式。在52期和55期进行的进一步重组实验表明，表皮信号负责在再生芽基中产生D-V模式。这些结果，连同在幼蛙前肢芽基中未发现Lmx-1表达这一发现，表明D-V轴的形成是理解再生能力丧失的关键步骤。
