Mechanisms underlying cell-fate patterns in yeast communities

项目总结/摘要 在我们的星球上，通信最初可能是作为单细胞微生物之间的化学信号进化而来的。一 现代微生物中这种类型的通信的基本目的是让这些微生物 to self-organize自我organize组织into functional功能communities社区.芽殖酵母S.酿酒，提供一个 有机会调查这种类型的社区组织，由于这种模式生物的无与伦比的 基因组注释和遗传可塑性。Honigberg实验室发现二倍体酵母菌群是 在减数分裂（孢子形成）细胞层下面组织成饲养细胞层。而且 细胞的相对数量和两层的尺寸取决于菌落环境。饲养细胞 可以通过向覆盖层的细胞提供营养物来刺激整个群落中的孢子形成。 除了其科学意义外，拟议研究的健康相关性还来自于 事实上，致病酵母生物膜的空间组织显著地有助于 医院获得性真菌感染此外，微生物群落组织的机制可以 有助于阐明人类组织和肿瘤的驱动力。 Honigberg实验室的一个长期目标是确定调节自我的机制， 从同质到高度模式化的社区的酵母菌落的组织。第一个具体目标 该应用程序是为了测试“差异分区提供环境缓冲区”假设， 确定集落中饲养细胞的数量是否与对这些饲养细胞的依赖性相关 细胞在一系列条件下形成孢子。此外，我们将确定是否建立和 维持差别划分取决于小区自主和小区非自主机制。 第二个具体目的是表征饲养细胞的表达模式的相似性， 培养物中发现的静止细胞，并检验集落中饲养细胞的数量 通过线粒体信号对殖民地的呼吸状态作出反应。 三个互补的方法来解决上述假设。第一 该方法测量了完整野生型中已知的饲养细胞特异性或孢子形成特异性基因的表达， 通过共聚焦或多光子荧光显微镜对分型或突变集落进行分析，并测量共定位 这些基因在来自重悬集落的细胞群中的表达。第二种方法检查分区 和其他标记的殖民地发展跨越2-D环境景观，即当两个 环境条件（例如温度或营养物浓度）都是变化的。第三 该方法使用FACS-Seq比较了饲养层和孢子形成细胞层中的基因表达模式。

Project Summary / Abstract Communication likely first evolved on our planet as chemical signals between single-cell microorganisms. A fundamental purpose for this type of communication in modern microorganisms is to allow these microbes to self-organize into functional communities. Colonies of the budding yeast, S. cerevisiae, provide an opportunity to investigate this type of community organization due to this model organism's peerless genome annotation and genetic malleability. The Honigberg lab discovered that diploid yeast colonies are organized into a layer of feeder cells underlying a layer of meiotic (sporulating) cells. Furthermore, the relative number of cells and dimensions of the two layers depends on colony environment. Feeder cells may stimulate sporulation in the overall community by providing nutrients to the cells of the overlying layer. In addition to its scientific interest, the health relevance of the proposed research derives from the fact that the spatial organization of pathogenic yeast biofilms contributes significantly to the lethality of hospital-acquired fungal infections. Furthermore, mechanisms of microbial community organization could help elucidate the forces driving organization of tissues and tumors in humans. A long-range goal of the Honigberg lab is to identify the mechanisms that regulate the self- organization of yeast colonies from homogeneous to highly patterned communities. The first specific aim of the application is to test the “Differential Partitioning provides Environmental Buffer” hypothesis by determining whether the number of feeder cells in colonies correlates with the dependency on these feeder cells for sporulation across a range of conditions. In addition, we will determine whether establishing and maintaining differential partitioning depends on both cell autonomous and cell nonautonomous mechanisms. The second specific aim is to characterize feeder cells with respect to the similarity of expression patterns to quiescent cells found in cultures, and to test the hypotheses that the number of feeder cells in colonies responds to the respiratory state of the colony through mitochondrial signaling. Three complementary approaches are employed to address the above hypotheses. The first approach measures expression of known feeder-cell specific or sporulation-specific genes within intact wild- type or mutant colonies by confocal or multi-photon fluorescent microscopy, and to measure co-localization of these genes in cell populations from resuspended colonies. The second approach examines partitioning and other markers of colony development across a 2-D environmental landscape, i.e. when two environmental conditions (such as temperature or concentration of nutrients) are both varied. The third approach compares gene expression patterns in feeder and sporulation cell layers using FACS-Seq.