Proteomic analysis of meiosis and characterization of novel short open reading frames in the fission yeast <i>Schizosaccharomyces pombe</i>

Meiosis is the process by which haploid gametes are produced from diploid precursor cells. We used stable isotope labeling by amino acids in cell culture (SILAC) to characterize the meiotic proteome in the fission yeast <i>Schizosaccharomyces pombe</i>. We compared relative levels of proteins extracted from cells harvested around meiosis I with those of meiosis II, and proteins from premeiotic S phase with the interval between meiotic divisions, when S phase is absent. Our proteome datasets revealed peptides corresponding to short open reading frames (sORFs) that have been previously identified by ribosome profiling as new translated regions. We verified expression of selected sORFs by Western blotting and analyzed the phenotype of deletion mutants. Our data provide a resource for studying meiosis that may help understand differences between meiosis I and meiosis II and how S phase is suppressed between the two meiotic divisions.

减数分裂是一类由二倍体前体细胞产生单倍体配子的生物学过程。本研究采用细胞培养氨基酸稳定同位素标记（SILAC）技术，对粟酒裂殖酵母（Schizosaccharomyces pombe）的减数分裂蛋白质组进行了系统表征。我们分别比较了减数分裂I期与减数分裂II期收获细胞中提取的蛋白质相对丰度，同时对比了减数分裂前S期与两次减数分裂间无S期的间期阶段的蛋白质相对水平。本研究的蛋白质组数据集鉴定到了对应于短开放阅读框（sORFs）的肽段，这类sORFs此前已通过核糖体谱分析被鉴定为新型翻译区域。我们通过免疫印迹（Western blotting）验证了部分筛选得到的sORFs的表达情况，并分析了其基因缺失突变体的表型。本研究数据为减数分裂相关研究提供了宝贵的资源，有助于解析减数分裂I与减数分裂II之间的差异，以及两次减数分裂间期S期被抑制的调控机制。