Abstract:
Regeneration is widespread across all animal taxa, but patterns of its distribution and key factors determining regeneration capabilities stay enigmatic. A comparative approach could shed light on the problem, but its efficacy is limited by the fact that data is only available on a few species from derived taxa. Pycnogonida are nested basally within the Chelicerata. They can shed and replace their walking legs and have a high regeneration capacity. In this work, we carried careful observation on leg appendotomy and regeneration processes in a sea spider under laboratory settings. The limb structure and in vivo observation reveal autotomy as the most likely appendotomy mechanism. High regeneration capabilities were ascertained: an anatomically normal but small leg appeared in a single molting cycle and the full functionality regained in 2-3 cycles. Wound closure after appendotomy in N. brevirostre primarily relies on hemolymph coagulation, which apparently differs from both xiphosurans and crustaceans. Regeneration is provided by proliferation in the leg cutpiece. Regenerative morphogenesis resembles the normal ontogenetic morphogenesis of a walking leg, but accelerated. Unlike in most arthropods, in N. brevirostre, regeneration does not necessarily correspond to the molting cycle, inferring a plesiomorphic state.
摘要:
再生在所有动物类群中都很普遍,但是它的分布方式和决定再生能力的关键因素仍然是神秘的。比较的方法可以揭示这个问题,但是其功效受到以下事实的限制:数据仅来自衍生分类群的少数物种。Pycnogonida在Chelicerata的基础上嵌套。它们可以脱落并更换行走的腿,并且具有很高的再生能力。在这项工作中,我们在实验室环境下对海蜘蛛的腿部阑尾切开术和再生过程进行了仔细观察。肢体结构和体内观察显示,自体切开术是最可能的阑尾切开术机制。确定了高再生能力:在单个蜕皮周期中出现了解剖学上正常但较小的腿,并且在2-3个周期中恢复了全部功能。短病毒奈瑟菌阑尾切开术后伤口闭合主要依靠血淋巴凝固,这显然有别于喜鱼和甲壳类动物。再生是通过腿部切割件的增殖提供的。再生形态发生类似于步行腿的正常个体发育形态发生,但加速。与大多数节肢动物不同,在N.Brevirostre,再生不一定对应于蜕皮周期,推断多态状态。