Li Chunyi, Suttie James M, Clark Dawn E
AgResearch Invermay Agricultural Centre, Mosgiel, New Zealand.
Anat Rec A Discov Mol Cell Evol Biol. 2005 Feb;282(2):163-74. doi: 10.1002/ar.a.20148.
Annual antler renewal presents the only case of epimorphic regeneration (de novo formation of a lost appendage distal to the level of amputation) in mammals. Epimorphic regeneration is also referred to as a blastema-based process, as blastema formation at an initial stage is the prerequisite for this type of regeneration. Therefore, antler regeneration has been claimed to take place through initial blastema formation. However, this claim has never been confirmed experimentally. The present study set out to describe systematically the progression of antler regeneration in order to make a direct histological comparison with blastema formation. The results showed that wound healing over a pedicle stump was achieved by ingrowth of full-thickness pedicle skin and resulted in formation of a scar. The growth centers for the antler main beam and brow tine were formed independently at the posterior and anterior corners of the pedicle stump, respectively. The hyperplastic perichondrium surmounting each growth center was directly formed in situ by a single type of tissue: the thickening distal pedicle periosteum, which is the derivative of initial antlerogenic periosteum. Therefore, the cells residing in the pedicle periosteum can be called antler stem cells. Antler stem cells formed each growth center by initially forming bone through intramembranous ossification, then osseocartilage through transitional ossification, and finally cartilage through endochondral ossification. There was an overlap between the establishment of antler growth centers and the completion of wound healing over the pedicle stump. Overall, our results demonstrate that antler regeneration is achieved through general wound healing- and stem cell-based process, rather than through initial blastema formation. Pedicle periosteal cells directly give rise to antlers. Histogenesis of antler regeneration may recapitulate the process of initial antler generation.
每年鹿角的更新是哺乳动物中仅有的形态发生再生（在截肢平面远端重新形成缺失附肢）的例子。形态发生再生也被称为基于芽基的过程，因为在初始阶段芽基的形成是这种再生类型的先决条件。因此，鹿角再生被认为是通过初始芽基形成发生的。然而，这一说法从未得到实验证实。本研究旨在系统描述鹿角再生的过程，以便与芽基形成进行直接的组织学比较。结果表明，蒂残端的伤口愈合是通过全层蒂皮肤向内生长实现的，并形成了瘢痕。鹿角主枝和眉枝的生长中心分别在蒂残端的后角和前角独立形成。覆盖每个生长中心的增生性骨膜直接由单一类型的组织原位形成：增厚的远端蒂骨膜，它是初始生鹿角骨膜的衍生物。因此，存在于蒂骨膜中的细胞可称为鹿角干细胞。鹿角干细胞通过首先通过膜内成骨形成骨，然后通过过渡性骨化形成骨软骨，最后通过软骨内成骨形成软骨，从而形成每个生长中心。鹿角生长中心的建立与蒂残端伤口愈合的完成之间存在重叠。总体而言，我们的结果表明，鹿角再生是通过一般的伤口愈合和基于干细胞的过程实现的，而不是通过初始芽基形成。蒂骨膜细胞直接产生鹿角。鹿角再生的组织发生可能重现了初始鹿角生成的过程。
