Shimoda Chikashi
Department of Biology, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
J Cell Sci. 2004 Jan 26;117(Pt 3):389-96. doi: 10.1242/jcs.00980.
In the yeasts Schizosaccharomyces pombe and Saccharomyces cerevisiae, sporulation involves de novo synthesis of forespore membrane (FSM) within the cytoplasm of mother cells. The FSM ultimately becomes the plasma membrane of the developing ascospores. Several protein components of the FSM have been identified. Visualization of these proteins has demonstrated the dynamic nature of the genesis and development of the FSM. It begins to develop at the differentiated outer plaque of the spindle pole bodies (SPBs) and extends outwards, encapsulating each of the haploid nuclei produced by meiosis. Several coiled-coil proteins are specifically recruited to the SPBs and play indispensable roles in FSM assembly. Temporal and spatial coordination of meiotic nuclear divisions and membrane assembly is of special importance. Comparison of the processes of FSM assembly in these yeasts shows that the basic mechanism has been conserved, even though the individual proteins involved are often different. Understanding these dynamic aspects of yeast sporulation will help to elucidate a general mechanism for the cellularization of cytoplasm containing multiple nuclei.
在粟酒裂殖酵母和酿酒酵母中，孢子形成涉及在母细胞胞质内从头合成前孢子膜（FSM）。FSM最终成为发育中孢子的质膜。已经鉴定出FSM的几种蛋白质成分。对这些蛋白质的可视化显示了FSM发生和发育的动态性质。它开始在纺锤体极体（SPB）分化的外斑处发育并向外延伸，包裹减数分裂产生的每个单倍体细胞核。几种卷曲螺旋蛋白被特异性招募到SPB，并在FSM组装中发挥不可或缺的作用。减数分裂核分裂和膜组装的时间和空间协调尤为重要。对这些酵母中FSM组装过程的比较表明，即使所涉及的个别蛋白质通常不同，基本机制也得以保留。了解酵母孢子形成的这些动态方面将有助于阐明含有多个细胞核的细胞质细胞化的一般机制。
