Plant Journal:中科院王台研究组揭示植物精细胞发育机制
2016年3月3日,国际植物学权威期刊《The plant Journal》在线发表中国科学院植物分子生理学重点实验室王台研究组在植物精细胞发育机制研究领域取得重要进展，王台研究组博士研究生杨浩为第一作者，王台研究员为论文通讯作者。
在高等植物雄性配子发育过程中，减数分裂后的小孢子经不对称分裂产生了形态和命运截然不同的两个子细胞：大的营养细胞和小的生殖细胞。后者位于营养细胞内，具有高度凝聚的染色质，经有丝分裂产生两个精细胞。这种不对称分裂发生的机制一直不清楚。王台研究组通过建立百合营养细胞核、生殖细胞核和精细胞核的分离方法，分离了不同细胞核制备了组蛋白，并比较了这些细胞之间组蛋白的差异，其结果显示32个组蛋白变体中5个H1变体、2个H2B变体、1个H3变体和1个H4变体仅在生殖细胞和精细胞中存在;发现生殖细胞和精细胞有相似的组蛋白表达谱和H3翻译后修饰模式，但与营养细胞的组蛋白表达谱和H3翻译后修饰模式却显著不同。该结果表明不对称有丝分裂之后的两个子细胞各自建立了不同的组蛋白模式，这种差异有可能是生殖细胞和精细胞个性特征建立的基础，为解析生殖细胞和精细胞发育机制奠定了基础。
图. 生殖细胞和精细胞特异的H2B变体(mgH2B, mgH2B.in)(a)、H3变体(H3.3-like)(b)和H4变体(mgH4)(c)的序列特征。
原文链接：
Proteomic analysis reveals the differential histone programs between male germline Cells and vegetative cells in Lilium davidii
原文摘要：
In flowering plants, male germline fate is determined after asymmetric division of the haploid microspore. Daughter cells have distinct fates: the generative cell (GC) undergoes further mitosis to generate sperm cells (SCs), and the vegetative cell (VC) terminally differentiates. However, our understanding of the mechanisms underlying germline development remains limited. Histone variants and modifications define chromatin states, and contribute to establishing and maintaining cell identities by affecting gene expression. Here, we constructed a lily protein database, then extracted and detailed histone entries into a comprehensive lily histone database. We isolated large amounts of nuclei from VCs, GCs and SCs from lily, and profiled histone variants of all five histone families in all three cell types using proteomics approaches. We revealed 92 identities representing 32 histone variants: six for H1, 11 for H2A, eight for H2B, five for H3 and two for H4. Nine variants, including five H1, two H2B, one H3 and one H4 variant, specifically accumulated in GCs and SCs. We also detected H3 modification patterns in the three cell types. GCs and SCs had almost identical histone profiles and similar H3 modification patterns, which were significantly different from those of VCs. Our study also revealed the presence of multiple isoforms, and differential expression patterns between isoforms of a variant. The results suggest that differential histone programs between the germline and companion VCs may be established following the asymmetric division, and are important for identity establishment and differentiation of the male germline as well as the VC.
作者：王台
