Goss R J, Holt R
Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912.
J Exp Zool. 1992 Apr 1;261(4):451-7. doi: 10.1002/jez.1402610412.
Postmetamorphic froglets of Xenopus laevis regenerate hypomorphic unbranched spikes from amputated arm stumps. These are composed primarily of cartilage, produced from blastemalike structures sparsely populated with cells and rich in connective tissue. Some consider these outgrowths to be an example of epimorphic regeneration produced from blastemas, albeit deficient ones. Others interpret them as a case of tissue regeneration derived from fibroblastemas augmented by chondrocytes and periosteal and perichondrial fibroblasts. To resolve these alternatives, forelimbs were amputated proximal to the wrist, skinned, and inserted through the body wall into the abdominal cavity. In the absence of skin, epidermal wound healing failed to occur and blastemas could not develop. After 2 months, by which time controls had regenerated spikes averaging 3.38 mm long, the denuded stumps had not given rise to outgrowths. They typically developed cartilaginous caps on the severed ends of the radius-ulna, and in rare cases formed amorphous growths of cartilage. If blastema formation is considered diagnostic of epimorphic regeneration and tissue regeneration can proceed in the absence of epidermal wound healing and blastema formation, these findings lead to the conclusion that Xenopus limb regeneration is epimorphic.
非洲爪蟾的变态后幼蛙能从截断的臂残端再生出低形态的无分支尖突。这些尖突主要由软骨构成，由细胞稀疏分布且富含结缔组织的芽基样结构产生。一些人认为这些长出物是由芽基产生的同形再生的一个例子，尽管是有缺陷的。另一些人则将它们解释为成纤维芽基衍生的组织再生情况，软骨细胞、骨膜和成软骨纤维细胞对其有增强作用。为了确定哪种观点正确，在前臂靠近腕部截断后，剥去皮肤，将其穿过体壁插入腹腔。由于没有皮肤，表皮伤口无法愈合，芽基也无法形成。两个月后，此时对照组再生出的尖突平均长3.38毫米，而裸露的残端并未长出任何东西。它们通常在桡尺骨的断端形成软骨帽，极少数情况下会形成无定形的软骨生长物。如果认为芽基形成是同形再生的诊断标准，并且组织再生可以在没有表皮伤口愈合和芽基形成的情况下进行，那么这些发现就得出结论：非洲爪蟾的肢体再生是同形再生。
