Development and evolution of vertebrate skeletal tissues

我研究鱼和青蛙胚胎的骨骼是如何形成的。我应该说是骨骼；几乎5亿年来，所有脊椎动物都有两块骨骼：一块外骨骼和一块内骨骼。你在博物馆里看到的大多数人类或恐龙的骨骼都是内侧(Endo)骨骼，它是以软骨为基础的，其中大部分被骨骼取代。您的手臂骨骼是内骨骼的一部分。第二具骨架原本在外面，外骨骼也是如此。最初，它由骨头和牙本质(牙齿中发现的组织)组成，要么是孤立的小板子，要么是融合成外部盔甲的板子。在进化过程中，一些板块作为牙齿下沉到地表以下，形成锁骨(锁骨)和头骨的一部分。这两具骨骼有着截然不同的发展和进化历史。目前，我们正在研究青蛙和鱼的骨骼发育。青蛙之所以令人着迷，是因为蝌蚪的骨骼是以软骨为基础的，而成年的骨骼是以骨骼为基础的。我们想知道蝌蚪头骨中有多少是遗传给成年青蛙的。如果没有携带，那么成年骨骼元素是不是由一系列不同于构成蝌蚪软骨骨架的细胞形成的？我们将软骨或骨骼特异的基因标记到绿色荧光蛋白(GFP)上，并将该结构注入青蛙卵中。由此产生的卵子有绿色的软骨或骨骼。如果这种结构被整合到制造卵子和精子的细胞中，那么下一代的骨骼也将发出绿色的光。通过使用不同的基因结构，我们可以追踪青蛙一生中制造不同骨骼组织的细胞。我们知道青蛙的骨骼组织--它们是软骨和骨。鱼的情况就不那么明显了，在鱼中，软骨和骨骼之间发生了转变。我们的FISH项目将确定骨骼组织的类型和组织之间的过渡。一旦知道，我们就使用基因探针来揭示构成这些组织的细胞群体。由于孵化场中多达30%的鱼可能因为骨骼畸形而无法进入市场，这使得这些鱼对潜在客户没有吸引力，这种方法对水产养殖业和经济具有潜在的意义。

I study how the skeleton of embryos of fish and frogs form. I should say skeletons; all vertebrates have had two skeletons for almost 500 million years; an exo- and an endoskeleton. Most of the human or dinosaur bones you see in a museum are the inside (endo) skeleton, which is based on cartilage, most of which is replaced by bone. Your arm skeleton is part of the endoskeleton. The second skeleton was originally on the outside and so is an exoskeleton. Originally it consisted of bone and dentine (the tissue found in teeth), either as small isolated plates or as plates fused into an external armor. During evolution, some plates sank below the surface as teeth and to form the clavicle (collar bone) and parts of the skull. These two skeletons have distinct developmental and evolutionary histories. Currently, we are investigating skeletal development in frogs and fish. Frogs are fascinating because the tadpole skeleton is based in cartilage but the adult skeleton is based on bone. We want to know how much of the tadpole skull skeleton is carried over to adult frogs. If not carried over then do adult skeletal elements form from a line of cells distinct from those that form the tadpole cartilaginous skeleton? We tag genes that are specific for cartilage or bone onto green fluorescent protein (GFP) and inject the construct into frog eggs. The resulting eggs have green cartilages or bones. If the construct is incorporated into cells that make eggs and sperm, then the skeleton of the next generation will also glow green. By using different gene constructs we can track cells making different skeletal tissues during the frog's lifetime. We know the skeletal tissues in frogs - they are cartilage and bone. The situation is much less clear-cut in fish, in which transitions between cartilage and bone occur. Our fish project will identify the types of skeletal tissues and transitions between tissues. Once known, we use gene probes to reveal the cell populations that make these tissues. Because as much as 30% of fish in hatcheries may never make it to market because of skeletal deformities that make the fish unattractive to potential customers, this approach has potential significance for the aquaculture industry and the economy.