IOS: Specification, Patterning and Evolution of the Animal-Vegetal Axis

动物发育早期的一个关键步骤是外胚层（产生表皮（皮肤）和中枢神经系统（脑/脊髓）的细胞）与内胚层（产生肠道和内脏的细胞）的分离。在大多数动物中，这一过程受到未受精卵中称为动物-植物（AV）轴的分子极性的强烈影响。一般来说，来源于卵的动物极的细胞产生外胚层，而来源于植物极的细胞产生内胚层。这种发育潜能的分离通常是由高度保守的信号级联的局部激活介导的，称为典型Wnt （cWnt）途径。AV卵的极性如何调节胚胎一端受限的cWnt信号激活尚不清楚，但PI的研究小组已经表明，在海胆和海葵Nematostella中，这一过程是通过一种关键的Wnt通路蛋白的局部“激活”而发生的，这种蛋白被称为Disheveled （Dvl）。利用生物化学技术，PI的小组已经确定了候选蛋白质，这些蛋白质被假设限制了Dvl在胚胎一端的活性。因此，本研究的目的是利用分子方法对鉴定的候选蛋白如何调节海胆和线虫的Dvl活性进行功能分析。这项工作将阐明调节动物胚胎中细胞潜能最早分离的分子机制，并为复杂动物的发育和进化提供关键的见解。这项研究涉及研究生和本科生，包括来自科学领域代表性不足群体的学生。公共宣传包括与当地一名公立高中教师合作的一个正在进行的项目，旨在让来自海地和中南美洲的新移民学生对生物学感兴趣。

An early critical step during animal development is the separation of ectoderm, cells that produce the epidermis (skin) and central nervous system (brain/spinal cord), from endomesoderm, the cells that produce the intestine and internal organs. In most animals this process is strongly influenced by a molecular polarity present in the unfertilized egg termed the Animal-Vegetal (AV) axis. In general, cells derived from the egg's animal pole produce ectoderm, while vegetal pole-derived cells produce endomesoderm. This separation of developmental potential is frequently mediated by localized activation of a highly conserved signaling cascade called the canonical Wnt (cWnt) pathway. How AV egg polarity regulates restricted activation of cWnt signaling at one pole of embryos is not well understood, but the PI's group has shown that in sea urchins and in the sea anemone Nematostella, this process occurs by the localized 'activation' of a key Wnt pathway protein called Disheveled (Dvl). Using biochemical techniques the PI's group has identified candidate proteins that are hypothesized to restrict Dvl activity to one end of the embryo. Hence, the goal of this research is to use molecular methods to functionally analyze how the identified candidate proteins regulate Dvl activity in sea urchins and Nematostella. This work will elucidate the molecular mechanisms that regulate the earliest separation of cell potential in animal embryos, and provide critical insight into the development and evolution of complex animals. The research involves graduate and undergraduate students, including students from groups under-represented in science. Public outreach includes an ongoing program with a local public high school teacher aimed at getting new immigrant students from Haiti and Central and South America interested in biology.