Deuterostome extracellular matrix structures (ossicles, tubes & gill bars): Evolution, composition and development.

我的计划试图了解细胞外基质结构(EMS)的同源性，以及它们如何在进化和发育时间尺度上发生变化。EMS包括骨架、管子、贝壳和刺条。古生物学家、发育生物学家、物理化学家、材料科学家、医学研究人员和海洋酸化科学家对它们进行了广泛的研究。所使用的材料和产生的形态如此之多，以至于连接不同类群中基本结构的公共线引起了相当大的兴趣。我研究了后口动物的EMS(骨骼、管子和鳃)。后口动物包括三个门；半口目是一小群海洋无脊椎动物，是棘皮目的姐妹群(共同形成了棘皮目)，棘皮目又是脊索纲的姐妹。半角类由两大类组成，一类是独居的橡子蠕虫，另一类是群居的双节翼形目(包括笔石类)。在我职业生涯的早期，我假设脊索状的鳃，包括无细胞分泌的胶原蛋白，是后口的一种多形性(祖先)特征，存在于橡子虫中，但在棘皮动物中消失了。在过去的5年里，我利用比较和功能形态学、分子发育、比较基因组学(包括发现咽和鳃发育基因的同时性)以及寒武纪有鳃的橡子虫化石的发现，找到了对这一假说的支持。如今，这一假设已被广泛接受。在这里，我建议采用同样的多学科方法来检验关于后口EMS起源和进化的三个假说(前两个是新颖的，可归因于我过去5年的NSERC计划)。我在橡子虫中发现了类似棘皮动物的骨骼听骨，这导致了

My program seeks to understand the homology of extracellular matrix structures (EMS) and how they change on evolutionary and developmental time scales. EMS include skeletons, tubes, shells and gill bars. They are widely investigated by paleontologists, developmental biologists, physical chemists, material scientists, medical researchers, and ocean acidification scientists. There are so many materials used and morphologies produced, that common threads connecting basic structures in different taxa are of considerable interest. I study EMS (skeletons, tubes and gill bars) in the deuterostomes. Deuterostomes include three phyla; the Hemichordata are a small group of marine invertebrates that are sister group to Echinodermata (that together form the ‘Ambulacraria’), which in turn is sister to the Chordata. Hemichordates are comprised of two major classes, the solitary acorn worms, and the colonial, tubicolous pterobranchs (including graptolites). Early in my career I hypothesized that chordate gills, including the acellular secreted collagen, are a deuterostome plesiomorphic (ancestral) trait, present in acorn worms, but lost in echinoderms. In the past 5-years I have found support for this hypothesis using comparative and functional morphology, molecular development, comparative genomics including the finding of synteny of pharynx and gill developmental genes, and the discovery of Cambrian fossil acorn worms with gills. Today this hypothesis is widely accepted. Here I propose to adopt the same multidisciplinary approach to test three hypotheses (the first two are novel and attributable to the past 5-years of my NSERC program) on the origin and evolution of deuterostome EMS. My discovery of echinoderm-like skeletal ossicles in acorn worms has led to