"Fin development in zebrafish: function, regulation and evolution of the actinodin gene family."

我的实验室对以斑马鱼（一种小型热带鱼）作为脊椎动物模型来理解肢体和鳍发育的分子机制很感兴趣。四足动物（哺乳动物、鸟类、两栖动物……）的四肢是从祖先鱼类的成对鳍进化而来的。它是如何发生的在很大程度上仍然未知。鱼鳍和四足动物四肢的发育有一些相似之处，但称为放线菌毛的刚性原纤维的形成，特别是在鱼鳍中，是鱼鳍和四肢之间的最初区别之一。我们最近发现了一个新的基因家族，我们将其命名为放线菌素，它编码放线菌毛菌的成分。有趣的是，这些基因只在鱼类中发现，在进化过程中在四足动物的基因组中丢失了。当我们在实验室中取消放线素的功能时，对鳍形成的影响向我们表明，这些基因在进化过程中的丧失有助于鳍向四肢的转变。我们现在将通过研究放线素如何与胶原蛋白（鳍原纤维的另一种化学成分）相互作用来研究放线素的作用。我们还将确定遗传机制负责放线素生产，特别是在鳍。最后，我建议研究是否可以将部分放线素蛋白加工成具有生物活性的小片段。对放线素基因家族的描述使我们有机会更好地了解鳍的发育，并为我们更好地了解鳍和肢体的进化提供了机会。

My laboratory is interested in understanding the molecular mechanism underlying limb and fin development using the zebrafish, a small tropical fish as a vertebrate model. The limbs of tetrapod species (mammals, birds, amphibians...) evolved from the paired fins of ancestral fish. How it happened is still largely unknown. The development of fish fins and of tetrapod limbs shows some similarities but the formation of rigid fibrils named actinotrichia, specifically in fish fins, is one of the first differences between fins and limbs. We recently identified a new family of genes that we named actinodin and that code for components of the actinotrichia. Interestingly, these genes are only found in fish and have been lost in the genomes of tetrapod species during evolution. When we abolish the function of actinodins in the laboratory, the consequences on fin formation suggest to us that the loss of these genes during evolution contributed to the transformation of fins into limbs. We will now investigate the role of the actinodins by studying how they interact with collagen, another chemical component of fin fibrils. We will also identify the genetic mechanisms responsible for actinodin production specifically in fins. Finally, I propose to investigate whether part of the actinodin protein can be processed into a small fragment with biological activity. Characterization of the actinodin gene family gives us the opportunity to better understand fin development and provide us with a better insight into fin and limb evolution.