Studies of naturally evolved regeneration

受伤后身体受损部位的再生能力是一个引人注目但却鲜为人知的现象。虽然一些硬骨鱼和蝾螈能够替换多种组织类型，但大多数其他物种却不能。一个新出现的例外是蜥蜴。300多年来，人们已经认识到许多蜥蜴可以自然再生一条替代尾巴。我的国家科学研究委员会资助的项目正在进行的研究发现了蜥蜴再生能力扩大的证据。更具体地说，我们确定豹壁虎，一种常见的宠物贸易蜥蜴，不断产生新的神经元和心肌细胞（心肌细胞），这两种细胞类型在哺乳动物中基本上是不可替代的。此外，我们发现壁虎还能愈合皮肤上的伤口，不会留下疤痕。这些数据为我们提供了令人兴奋的新见解，了解了跨多个器官自发恢复组织结构和功能的机制。

The ability to regenerate damaged body parts following injury is a dramatic but poorly understood phenomenon. While some species of bony fish and salamanders are capable of replacing multiple tissue types, most other species cannot. One emerging exception is lizards. For more than 300 years it has been recognized that many lizards can naturally regenerate a replacement tail. Ongoing research by my NSERC-funded program has discovered evidence of an expanded regenerative repertoire in lizards. More specifically, we determined that the leopard gecko, a common pet trade lizard, constantly makes new neurons and cardiac muscle cells (cardiomyocytes), two cell types that are essentially irreplaceable in mammals. In addition, we discovered that geckos also heal wounds to the skin without scarring. These data provide us with exciting new insight into the mechanisms responsible for spontaneously restoring tissue structure and function across multiple organs. The long-term goal of my research program is to identify and understand the biological mechanisms that permit and promote the structural and functional replacement of damaged tissues. To achieve this goal, we study the diverse and naturally occurring regenerative abilities of lizards. Our short-term objectives are to determine the cellular mechanisms and functional consequences involved in regenerating three distinct organs: the heart, brain, and skin. We hypothesize that regeneration is a tissue/organ-specific process that emphasizes functional restoration over precise structural replication. This innovative research program is essential for addressing one of the most challenging questions in biology: why do some tissues, organs, and species regenerate while others do not. Comparative studies, such as those involving lizards, are the gold standard for regeneration research. Further, this program will allow us to probe the evolution and diversity of self-repair mechanisms. Beyond regenerative biology, this research provides important contributions to the fields of stem cell and developmental biology. We anticipate that leopard geckos are capable of regenerating portions of the heart, brain, and skin, and that these exceptional abilities will reveal an unexpected diversity of reparative mechanisms. Knowledge acquired during this research is critical for a more complete understanding of how tissues can be naturally rebuilt after injury. This research has obvious benefits for biologists and biomedical scientists, with important implications for translational medicine. We are global leaders in the field of reptile regeneration, with unique expertise in lizard biology, surgery, histology, and behavior. We have a proven track record of public engagement, scientific communication, and recruiting highly qualified personnel of diverse backgrounds. The originality and charisma of the leopard gecko model has proven successful in recruiting students and promoting public interest in science.