Analysis of gene expressions during Xenopus forelimb regeneration
Analysis of gene expressions during Xenopus forelimb regeneration
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DOI：
10.1006/dbio.2000.9641
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发表时间：
2000-04-15
影响因子：
2.7
通讯作者：
Ide, H
中科院分区：
文献类型：
--
作者：
Endo, T;Tamura, K;Ide, H
非洲爪蟾在肢芽的早期阶段可以完全再生被截肢的肢体，但蜕变的小蛙逐渐失去这种能力，只能再生一个尖刺状的结构。我们的研究表明，爪蟾幼体的尖刺形成与尾尾动物的肢体再生一样依赖于神经，因为伴随截肢的去神经支配足以抑制胚泡形成和表皮中fgf8的表达。此外，为了确定再生能力降低的原因，我们检测了在穗状结构形成过程中肢体模式的几个关键基因的表达模式，并将它们与产生完整肢体结构的肢体芽发育和再生中的基因进行了比较。我们克隆了Xenopus HoxA13，这是一个未来的足部区域标记，表达模式表明，小蛙的尖状结构伴随着近端远端（PD）轴的延伸和图案。另一方面，在表达fgf8和msx1的小青蛙胚中未检测到shh的表达。因此，虽然伤口表皮可能诱导小青蛙胚基的生长，但组织前后轴形成的极化活动可能在那里不存在。我们的研究结果表明，小青蛙肢体的缺失区域沿着PD轴再生，而AP模式组织的失败会导致小青蛙体内出现尖峰状的不完整结构，这表明再生能力与AP模式之间存在关系。这些发现使我们得出结论，爪蟾肢体变形后的尖刺形成是一种表形再生。(C) 2000年学术出版社。
Xenopus laevis can regenerate an amputated limb completely at early limb bud stages, but the metamorphosed froglet gradually loses this capacity and can regenerate only a spike-like structure. me show that the spike formation in a Xenopus froglet is nerve dependent as is limb regeneration in urodeles, since denervation concomitant with amputation is sufficient to inhibit the initiation of blastema formation and fgf8 expression in the epidermis. Furthermore, in order to determine the cause of the reduction in regenerative capacity, we examined the expression patterns of several key genes for limb patterning during the spike-like structure formation, and we compared them with those in developing and regenerating limb buds that produce a complete Limb structure. We cloned Xenopus HoxA13, a marker of the prospective antopodium region, and the expression pattern suggested that the spike-like structure in froglets is accompanied by elongation and patterning along the proximodistal (PD) axis. On the other hand, shh expression was not detected in the froglet blastema, which expresses fgf8 and msx1. Thus, although the wound epidermis probably induces outgrowth of the froglet blastema, the polarizing activity that organizes the anteroposterior (AP) axis formation is likely to be absent there. Our results demonstrate that the lost region in froglet limbs is regenerated along the PD axis and that the failure of organization of the AP pattern gives rise to a spike-like incomplete structure in the froglet, suggesting a relationship between regenerative capacity and AP patterning. These findings lead us to conclude that the spike formation in postometamorphic Xenopus limbs is epimorphic regeneration. (C) 2000 Academic Press.