Gene Expression in Giardia lamblia

多细胞生物（如人类）的每个细胞都包含相同的基因蓝图——那么是什么使血细胞与肌肉细胞不同呢？答案是遗传物质是如何被激活的。不同的细胞类型会激活不同的基因来制造特定细胞功能的蛋白质。例如，血细胞会产生一种蛋白质，用于将氧气输送到全身，而肌肉细胞会产生一种蛋白质，用于细胞收缩。这种差异基因激活的过程被称为基因表达。我们研究的长期目标是研究原生鞭毛虫（贾第鞭毛虫）基因表达的调控。贾第鞭毛虫是世界各地包括加拿大所有地区的淡水中常见的污染物，人类摄入贾第鞭毛虫会导致传染性腹泻。贾第鞭毛虫是一种真核生物，就像人类细胞一样，因为它的基因位于细胞内一个叫做细胞核的特殊区域。然而，贾第鞭毛虫体内调节基因表达和其他生物途径所需的成分（即蛋白质）大大减少，而且比人类体内的成分更简单。因此，贾第鞭毛虫的研究将是一个机会，可以在一个流线型生物系统中确定这些过程的基本要素。此外，这些研究可能确定贾第鞭毛虫这些途径的独特方面，可用于开发改进和更有效的贾第鞭毛虫感染治疗方法。我们的短期目标是：1)研究贾第鞭毛虫细胞周期的基因表达和调控——细胞生长和分裂产生两个子细胞的过程。2)描述贾第鞭毛虫蛋白（TBP）在转录调控中的作用，转录调控是指相应基因产生RNA的过程。3)探讨三种相关血红素蛋白在贾第鞭毛虫基因表达调控及向感染形式转化中的作用。这项NSERC拨款将支持一项令人兴奋的基础研究计划，以了解在加拿大常见的寄生虫如何决定其遗传物质的哪一部分被激活以制造功能性产品。拨款亦会支持培训研究生和本科生掌握分子生物学、微生物学和生物化学的前沿技术。

Every cell within a multicellular organism, such as a human, contains the same genetic blueprint - so what makes a blood cell different from a muscle cell? The answer is how the genetic material is activated. Different cell types activate different sets of genes to make proteins that are specific for the function of the particular cell. For example, a blood cell would produce a protein for carrying oxygen through the body, while a muscle cell would produce a protein that is used for cell contraction. The process of this differential gene activation is referred to as gene expression. The long term goal of our research is to study the regulation of gene expression in the protist, Giardia lamblia (syn. G. intestinalis). Giardia is a common contaminant of freshwaters worldwide including all regions in Canada, and its ingestion by humans causes an infectious form of diarrhea. Giardia is a eukaryote, like a human cell, because its genes are located in a special compartment within the cell called the nucleus. However, the components (i.e. proteins) required to regulate gene expression and other biological pathways in Giardia are greatly reduced and less complex than those in a human. Therefore, the study of Giardia would be an opportunity to identify the bare essentials of these processes in a streamlined biological system. Moreover, these studies may identify unique aspects of these pathways in Giardia that can be exploited to develop improved and more effective treatments of Giardia infections. Our short-term aims for this granting period are: 1) To study gene expression and regulation of the Giardia cell cycle - a process where the cell grows and divides to produce two daughter cells. 2) To characterize the role of a Giardia protein (TBP) in transcription regulation - the process when RNA is produced from its corresponding gene. 3) To examine the role of three related heme proteins in the regulation of gene expression and the transition of Giardia into its infectious form. This NSERC grant would provide support to an exciting and fundamental research program to understand how a parasite commonly found in Canada determines which part of its genetic material gets activated to make a functional product. The funding would also support the training of graduate and undergraduate students in leading edge techniques in molecular biology, microbiology and biochemistry.