一直以来基因学家都在努力复制鱼儿长腿这一神秘的进化历程，这也是揭开2亿年前脊椎动物从水生演进到陆生从而接管地球之谜关键。现在他们终于成功了，他们成功让鱼儿长出腿。
西班牙保罗·德·奥拉维德大学的遗传研究人员发现，鱼鳍细胞中引入HOXD13基因后，鱼发育出的肢体更像是一条腿。
科学家用斑马鱼进行了试验，他们将额外的HOXD13基因引入斑马鱼坯胎的鱼鳍顶端，该基因促成了新软骨组织的产生和鱼鳍组织的减少，进而发育出“鱼腿”。
据了解，HOXD13基因控制了我们的身体结构，决定了我们的手指数量、形状和腿部形状。如果该基因受损，会导致严重的肢体畸形。
科学家们一直致力于再现生命从海洋进化到陆地的步骤，西班牙的这项研究成果有望推动揭开这一神秘面纱。
Hoxd 13 Contribution to the Evolution of Vertebrate Appendages
Renata Freitas, Carlos Gómez-Marín, Jonathan Mark Wilson, Fernando Casares, José Luis Gómez-Skarmeta
Fossil data suggest that limbs evolved from fish fins by sequential elaboration of their distal endoskeleton, giving rise to the autopod close to the tetrapod origin. This elaboration may have occurred by a simultaneous reduction of the distal ectodermal fold of fish fins. Modulation of 5′Hoxd gene transcription, through tetrapod-specific digit enhancers, has been suggested as a possible evolutionary mechanism involved in these morphological transformations. Here, we overexpress hoxd13a in zebrafish to investigate the impact of increasing 5′Hoxd expression during fin development. This overexpression causes increased proliferation, distal expansion of chondrogenic tissue and finfold reduction. In addition, we also show that the tetrapod-specific 5′Hoxd enhancer CsC promotes similar expression in zebrafish fins and mouse limbs. Our results support the idea that modulation of 5′Hoxd gene expression, by acquisition of novel enhancer elements, offered the substrate for the evolution of fins and the origin of tetrapod limbs.
文献链接：Hoxd13 Contribution to the Evolution of Vertebrate Appendages
