Salamanders在四足动物(四足脊椎动物)中显示出无与伦比的组织再生能力,能够修复和更新丢失或损坏的车身零件,比如尾巴,下巴,四肢看起来很完美。尽管对axolotl(Ambystomamexicanum)再生进行了无数的研究,到目前为止,只有少数研究比较了原始和再生肢体骨骼的总体形态和组织学特征。其中,大多数研究都集中在神经或肌肉上,而更少的人提供了关于骨骼和软骨的详细信息。这项研究根据组织水平组织学比较了原始和再生肢体的骨骼组织结构。产生了55只axolotl幼虫的组织学连续切片,包括29个被物种切断的肢体,和26个有针对性的截肢。在几个幼虫阶段(48、52和53)和不同的肢体位置(肱骨中轴,在中足类动物上方)。此外,基于X射线显微断层摄影扫描制备3D重建。结果表明,由于不完全再生,再生的前肢显示出肢体和手指异常的多样性。此外,与截肢后的再生前肢相比,自然咬伤引起的再生前肢异常更严重,更频繁。结果表明,幼虫腋窝再生后经常出现异常,这与通常导致完美四肢的再生观念相矛盾。
Salamanders show unparalleled capacities of tissue regeneration amongst tetrapods (four-legged vertebrates), being able to repair and renew lost or damage body parts, such as tails, jaws, and limbs in a seemingly perfect fashion. Despite countless studies on
axolotl (Ambystoma mexicanum) regeneration, only a few studies have thus far compared gross morphological and histological features of the original and regenerated limb skeleton. Therein, most studies have focused on nerves or muscles, while even fewer have provided detailed information about bones and cartilage. This
study compares skeletal tissue structures of original and regenerated limbs with respect to tissue level histology. Histological serial sections of 55
axolotl larvae were generated, including 29 limbs that were severed by conspecifics, and 26 that were subject to targeted amputations. Amputations were executed in several larval stages (48, 52, and 53) and at different limb positions (humeral midshaft, above the mesopod). In addition, 3D reconstructions were prepared based on X-ray microtomography scans. The results demonstrate that regenerated forelimbs show a diversity of limb and digit abnormalities as a result of imperfect regeneration. Furthermore, abnormalities were more severe and more frequent in regenerated forelimbs caused by natural bites as compared with regenerated forelimbs after amputation. The results indicate that abnormalities occur frequently after regeneration in larval axolotls contradicting the notion of regeneration generally resulting in perfect limbs.