Mating, Self-Fertility, and Meiosis in Yeast

智力价值：有性繁殖是真核生物系统中的主要繁殖方式，从单细胞酵母细胞到哺乳动物生物。该项目的目标是了解酵母中调控有性繁殖的机制的多样性，并确定这些机制的变化如何导致不同的有性繁殖模式。我们对性生物学的大部分了解都来自于对模型酵母--酿酒酵母的研究。然而，现在很明显的是，其他半子囊菌酵母在其性生活方式上与酿酒酵母表现出了基本的差异。本项目将通过比较半子囊菌的念珠菌分支中多个物种的有性繁殖机制来分析这些差异。这些酵母菌代表了不同的酵母种类，包括那些具有传统的性程序(交配发生在两个异性之间)的酵母，那些能够进行自体受精的酵母，以及那些可能完全无性的酵母。这个项目将研究通过性信息素发出的信号如何调节不同种类的酵母的自交(近亲繁殖)和近亲繁殖。此外，还将对白念珠菌的减数分裂机制进行探讨。该物种经历了一种有效的减数分裂染色体减少程序，但缺乏许多调控酿酒酵母减数分裂的关键基因。这项研究的完成将揭示性生活方式如何被修改或重新编程，以促进密切相关的酵母物种之间的替代生活方式。广泛的影响：该项目将引入两个广泛的主题，促进教育和研究中的科学整合。首先，来自少数族裔的高中生将获得微生物学奖学金，来到布朗大学，参加大学前的暑期班，以及项目负责人实验室的全日制研究项目。项目负责人还将在这些奖学金的后续行动中，参加研究员的高中，与其他对生物科学研究有普遍兴趣的学生见面并鼓励他们。第二种方法是为布朗大学的本科生提供更多的研究机会。暑期奖学金将用于激发本科生对微生物学和遗传学的兴趣，特别是指导来自代表性不足的少数族裔的学生。

Intellectual Merit: Sexual reproduction is the predominant mode of reproduction in eukaryotic systems, from single-celled yeast cells to mammalian organisms. The goal of this project is to understand the diversity of mechanisms that regulate sexual reproduction in yeast, and to determine how changes in these mechanisms can lead to distinct modes of sexual reproduction. Much of our understanding of sexual biology has been derived from work on the model yeast, Saccharomcyes cerevisiae. However, it is now apparent that other hemiascomycete yeast exhibit elemental differences in their sexual lifestyles to that of S. cerevisiae. This project will analyze these differences by comparing mechanisms of sexual reproduction in multiple species from the Candida clade of hemiascomycetes. These represent a diverse collection of yeast species, including those with traditional sexual programs (mating occurs between two partners of opposite sex), those that are able to undergo self-fertilization, and those that may be completely asexual. This project will examine how signaling via sexual pheromones regulates self-fertilization (inbreeding) as well as outbreeding in different species of yeast. In addition, the mechanism of meiosis will be addressed in Candida lusitaniae. This species undergoes an efficient program of meiotic chromosome reduction but is lacking many of the key genes regulating meiosis in S. cerevisiae. Completion of this research will reveal how sexual lifestyles can be modified or re-programmed to promote alternative lifestyles amongst closely related species of yeast.Broader Impacts: This project will introduce approaches that foster integration of science in education and research using two broad themes. First, high school students from underrepresented minorities will be given Microbiology Fellowships to come to Brown University and participate in pre-college summer classes as well as full-time research projects in the project leader's laboratory. The project leader will also follow-up these fellowships by attending the fellows' high school to meet and encourage other students with a general interest in research in the biological sciences. The second approach will be to further the research opportunities for undergraduate students at Brown. Summer fellowships will be used to stimulate undergraduate interest in microbiology and genetics, and in particular to mentor students from underrepresented minorities.