MOLECULAR GENETICS OF PARAMECIUM

草履虫在一些动物现象的研究中具有优势，并且非常适合生物电和细胞行为的遗传解剖。在过去的30年里，具有缺陷的Ca2+电流，K+电流和Na+电流的突变体已经被分离出来并表现出表型特征。我们最近开发了一种方法来系统地克隆草履虫基因对应的表型。这种方法需要表型互补，并保证克隆的基因在其生物学背景下具有功能。我们计划用这种方法从上述突变体中获取基因。我们克隆了控制纤毛Ca2+电流的pwA和pwB基因。根据预测基因产物的特征，我们将继续测试其生化功能。这些和其他基因产物可能为纤毛和精子尾部的信号转导和Ca2+代谢提供见解。基因也可以通过与其他生物已知基因的同源性来克隆。我们将继续寻找方法，通过敲除这些同源基因来创造活的草履虫突变体。将尝试三种方法：基因沉默，kimeraplasty和内部消除序列的操作。由于这是一种方便的转化方法，有利于整个社区的研究，我们还计划完善草履虫的大规模转化方法。

Paramecium offers advantages in the study of several animal phenomena and is well suited for the genetic dissection of bioelectricity and cell behavior. Over the last 30 years, mutants with defective Ca2+ currents, K+ currents and Na+ currents have been isolated and characterized phenotypically. We have recently developed a method to systematically clone Paramecium genes that correspond to phenotypes. This method entails phenotypic complementation and guarantees the genes cloned to be functional in their biological context. We plan to use this method to harvest the genes from the above mutants. We have cloned the pwA and pwB genes that control the ciliary Ca2+ currents. Based on features of the predicated gene products, we will continue to test their biochemical functions. These and other gene products may give insights to signal transductions and Ca2+ metabolism in cilia and sperm tail. Genes have also been cloned by their homology to known genes of other organisms. We will continue to find ways to create live Paramecium mutants with these homologous genes knocked out. Three methods will be tried: gene silencing, kimeraplasty, and the manipulation of internal eliminated sequences. Because a convenient transformation method with facilitate research of the whole community, we also plan to perfect methods of transforming paramecia en masse.