Tank P W, Carlson B M, Connelly T G
J Exp Zool. 1977 Sep;201(3):417-29. doi: 10.1002/jez.1402010308.
A comparison between the surface features of embryonic limb development and limb regeneration was made in the axolotl. Scanning electron microscopy revealed an overall similarity between embryonic and regenerating limbs. A notable feature was the lack of a morphologically discrete apical epidermal specialization on the surface of any of the limbs. Histological preparations revealed no thickening of the apical epidermis in embryonic limbs. There is a definite thickening of the apical epidermis in regenerating limbs during the stages of dedifferentiation and the early blastemal phases, but the thickening projects into the underlying tissues rather than altering the smooth surface contours of the blastema. Minor differences in epidermal specializations (ciliated cells scattered over the entire body and very irregularly shaped cells with knob-like projections at the tips of digits in embryos) may be attributable to differences in overall activity of the animals at various stages in their life history.
对美西螈胚胎肢体发育和肢体再生的表面特征进行了比较。扫描电子显微镜显示胚胎肢体和再生肢体之间总体相似。一个显著特征是任何肢体表面都缺乏形态上离散的顶端表皮特化结构。组织学切片显示胚胎肢体的顶端表皮没有增厚。在再生肢体的去分化阶段和早期芽基阶段，顶端表皮有明显增厚，但增厚部分向下方组织突出，而不是改变芽基的光滑表面轮廓。表皮特化的细微差异（胚胎全身散布的纤毛细胞以及手指尖端有瘤状突起的形状非常不规则的细胞）可能归因于动物在其生命史不同阶段的总体活动差异。
