Comparative Histolab Padova, Italy.
J Morphol. 2020 Nov;281(11):1358-1381. doi: 10.1002/jmor.21251. Epub 2020 Aug 31.
This review elaborates the idea that organ regeneration derives from specific evolutionary histories of vertebrates. Regenerative ability depends on genomic regulation of genes specific to the life-cycles that have differentially evolved in anamniotes and amniotes. In aquatic environments, where fish and amphibians live, one or multiple metamorphic transitions occur before the adult stage is reached. Each transition involves the destruction and remodeling of larval organs that are replaced with adult organs. After organ injury or loss in adult anamniotes, regeneration uses similar genes and developmental process than those operating during larval growth and metamorphosis. Therefore, the broad presence of regenerative capability across anamniotes is possible because generating new organs is included in their life history at metamorphic stages. Soft hyaluronate-rich regenerative blastemas grow in submersed or in hydrated environments, that is, essential conditions for regeneration, like during development. In adult anamniotes, the ability to regenerate different organs decreases in comparison to larval stages and becomes limited during aging. Comparisons of genes activated during metamorphosis and regeneration in anamniotes identify key genes unique to these processes, and include thyroid, wnt and non-coding RNAs developmental pathways. In the terrestrial environment, some genes or developmental pathways for metamorphic transitions were lost during amniote evolution, determining loss of regeneration. Among amniotes, the formation of soft and hydrated blastemas only occurs in lizards, a morphogenetic process that evolved favoring their survival through tail autotomy, leading to a massive although imperfect regeneration of the tail. Deciphering genes activity during lizard tail regeneration would address future attempts to recreate in other amniotes regenerative blastemas that grow into variably completed organs.
这篇综述阐述了这样一种观点，即器官再生源于脊椎动物特定的进化历史。再生能力取决于特定于生活周期的基因的基因组调控，这些基因在无羊膜动物和羊膜动物中经历了不同的进化。在鱼类和两栖动物生活的水生环境中，在达到成年阶段之前会发生一次或多次变态过渡。每次过渡都涉及到幼虫器官的破坏和重塑，这些器官被成年器官所取代。在成年无羊膜动物的器官受伤或丢失后，再生利用的基因和发育过程与幼虫生长和变态过程中使用的基因和发育过程相似。因此，无羊膜动物广泛存在再生能力是可能的，因为在变态阶段的生命史中包括产生新器官。富含透明质酸的软再生芽基在浸没或水合环境中生长，这是再生的必要条件，就像在发育过程中一样。在成年无羊膜动物中，与幼虫阶段相比，再生不同器官的能力下降，并在衰老过程中受到限制。对无羊膜动物变态和再生过程中激活的基因进行比较，可以确定这些过程特有的关键基因，包括甲状腺、Wnt 和非编码 RNA 发育途径。在陆地环境中，一些基因或发育途径在羊膜动物进化过程中发生了变态过渡，导致了再生的丧失。在羊膜动物中，只有蜥蜴形成软的和水合的芽基，这是一个形态发生过程，有利于它们通过自切尾巴而生存，从而导致尾巴的大量但不完全的再生。在蜥蜴尾巴再生过程中解析基因的活性，将有助于未来尝试在其他羊膜动物中重现生长成各种完成器官的再生芽基。
