Exploring the evolution of the Contractile Vacuole.

细胞内物质的运动以及输入、输出和细胞表面呈现都是由膜运输系统(MTS)调节的。无论是对农业有重要意义的植物、对经济有影响的寄生虫，还是对生态系统平衡至关重要的藻类和原生动物，其适当和成功的操作都是有效的细胞功能的基础。进化MTS是建立真核细胞结构和产生我们今天看到的几乎所有生物多样性的关键。 我的研究项目考察了推动MTS演变的模式和过程。这项工作提供了对塑造我们细胞历史的基本力量的洞察，并产生了关于现代细胞生物学的重要信息。有趣的是，我们发现了广泛存在于动物和真菌之外的蛋白质机制：在不同的真核生物中，膜运输的细胞生物学可能与特征良好的模型系统不同，这些方式才刚刚开始被理解。类似地，虽然一些膜运输细胞器在真核生物中是保守的，但人们对细胞器知之甚少，存在于成熟的探索的众所周知的模型系统之外。 收缩液泡(CV)是一种渗透调节细胞器，存在于重要的淡水和土壤生物体内。然而，它通常不存在于寄生虫或海洋生物中，这引发了人们的疑问：被鉴定为收缩空泡的细胞器在不同的真核生物之间是否真的是同源的。 我们将使用分子进化和转录分析，通过两个短期目标来检查CV的进化和功能，每个短期目标都有定义的子项目。 1：为了检验最简单的零假设，即CV来自单一同源祖先，将调查来自真核细胞树的具有CV的真核生物样本。转录组学将用于确定渗透胁迫诱导血管紧张素转换酶功能时差异表达的基因。这些基因的同一性和进化将通过明确的预测来评估，即与CV功能相关的共同核心基因集将意味着同源性。2：为了补充这一广泛的分类方法，分析将集中在拥有特征良好的简历的单一谱系-纤毛虫。纤毛虫整个分类范围内的分子进化和转录组将评估在CV功能上保守的机制，再次预测存在保守的核心集。 通过鉴定在CV功能中重要的基因及其在真核生物中的分布，我们获得了存在于真核生物生态关键谱系中的细胞器的工作原理的信息。通过了解CV的进化，我们将能够将一个重要的细胞器整合到膜运输进化的更大框架中，并更好地理解地球上真核生物的兴起。

Movement of material within the cell, as well as import, export, and cell surface presentation is mediated by the membrane trafficking system (MTS). Its appropriate and successful operation underpins effective cellular function, whether in plants of agricultural importance, parasites of economic impact or algae and protists key to ecosystem balance. Evolving an MTS was key to establishing the eukaryotic cellular configuration and giving rise to nearly all of the biological diversity that we see today. My research program examines the patterns and processes driving the evolution of the MTS. This work provides insights into the fundamental forces that shaped our cellular history and yields important information about modern cell biology. Intriguingly, we have uncovered protein machinery widely present outside of animals and fungi: the cell biology of membrane-trafficking in diverse eukaryotes may differ from well-characterized model systems in ways that are only beginning to be understood. Similarly, while some membrane-trafficking organelles are conserved across eukaryotes, poorly understood organelles are present outside the well-known model systems that are ripe for exploration. The Contractile Vacuole (CV) is an osmoregulatory organelle found in ecologically important freshwater and soil-dwelling organisms. However, it is often not reported as present in parasites or marine organisms, raising questions of whether organelles identified as contractile vacuoles are truly orthologous between diverse eukaryotes. We will use molecular evolutionary and transcriptomic analysis to examine the evolution and function of the CV by two short-term goals, each with sub-projects defined within them. 1: In order to test the simplest null hypothesis that the CV derived from a single homologous ancestor, a sampling of eukaryotes with CVs from across the eukaryotic tree will be investigated. Transcriptomics will be used to determine genes that are differentially expressed upon induction of CV function by osmotic stress. The identity and evolution of these genes will be assessed with the explicit prediction that a common core gene set associated with CV function would imply homology. 2: To complement this taxonomically broad approach, analysis will be focused on a single lineage possessing well-characterized CVs, the ciliates. Molecular evolutionary and transcriptomics across the full taxonomic range of ciliates will assess the machinery that is conserved in CV function, again predicting the presence of a conserved core set. By identifying the genes of importance in CV function and their distribution in eukaryotes, we gain information about the workings of an organelle present in ecologically crucial lineages of eukaryotes. By understanding the evolution of the CV, we will be able to integrate an important organelle into the larger framework of membrane-trafficking evolution and gain a better understanding into the rise of eukaryotic life on Earth.