Gammie Alison E
Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
Methods Mol Biol. 2008;475:197-211. doi: 10.1007/978-1-59745-250-2_11.
The process of creating a single cell from two progenitor cells requires molecular precision to coordinate the events leading to cytoplasmic continuity while preventing lethal cell lysis. Cell fusion characteristically involves the mobilization of fundamental processes, including signaling, polarization, adhesion, and membrane fusion. The yeast Saccharomyces cerevisiae is an ideal model system for examining the events of this critical and well-conserved process. Researchers employ yeast cells because they are rapidly growing, easy to manipulate, amenable to long-term storage, genetically tractable, readily transformed, and nonhazardous. The genetic and morphological characterizations of cell fusion in wild-type and fusion mutants have helped define the mechanism and temporal regulation required for efficient cell fusion. Ultrastructural studies, in particular, have contributed to the characterization of and revealed striking similarities within cell fusion events in higher organisms. This chapter details two yeast cell fusion ultrastructural methods. The first utilizes an ambient temperature chemical fixation, and the second employs a combination of high-pressure freezing and freeze substitution.
由两个祖细胞生成单个细胞的过程需要分子层面的精确性，以协调导致细胞质连续的事件，同时防止致命的细胞裂解。细胞融合的特征在于调动包括信号传导、极化、黏附及膜融合在内的基本过程。酿酒酵母是用于研究这一关键且保守过程中各项事件的理想模型系统。研究人员选用酵母细胞，是因为它们生长迅速、易于操作、便于长期保存、具有遗传易处理性、易于转化且无危害。对野生型和融合突变体中细胞融合的遗传和形态学特征进行的研究，有助于明确高效细胞融合所需的机制和时间调控。特别是超微结构研究，有助于对高等生物细胞融合事件进行特征描述，并揭示其中显著的相似性。本章详细介绍两种酵母细胞融合超微结构方法。第一种方法利用常温化学固定，第二种方法采用高压冷冻和冷冻置换相结合的方式。
