Department of Plant Sciences, South Parks Road. Oxford, OX1 3RB, UK.
Biol Rev Camb Philos Soc. 2009 Nov;84(4):589-615. doi: 10.1111/j.1469-185X.2009.00088.x. Epub 2009 Sep 2.
Alternation of generations underpins all plant life histories and is held to possess important adaptive features. A wide range of data have accumulated over the past century which suggest that alternation from sporophyte to gametophyte in angiosperms includes a significant phase of 'informational reprogramming', leaving the founder cells of the gametophyte developmentally uncommitted. This review attempts to bring together results from these historic studies with more recent data on molecular and epigenetic events which accompany alternation, gametophyte development and gametogenesis in angiosperms. It is striking that most members of the other principal group of multicellular eukaryotes--the animals--have a completely different a life history: animals generate their gametes directly from diploid germlines, often set aside early in development. Nevertheless, a comparison between animal germlines and angiosperm gametophyte development reveals a number of surprising similarities at the cytological and molecular levels. This difference in life history but similarity in developmental process is reviewed in the context of the very different life strategies adopted by plants and animals, and particularly the fact that plants do not set aside diploid germlines early in development.
世代交替是所有植物生活史的基础，被认为具有重要的适应特征。在过去的一个世纪里，积累了大量的数据，这些数据表明，被子植物从孢子体到配子体的交替包括一个重要的“信息重编程”阶段，使得配子体发育的起始细胞没有发育承诺。本综述试图将这些历史研究的结果与最近关于伴随被子植物世代交替、配子体发育和配子发生的分子和表观遗传事件的数据结合起来。引人注目的是，其他主要的多细胞真核生物群体——动物——的大多数成员都有一个完全不同的生活史：动物直接从二倍体生殖系产生配子，通常在发育早期就被搁置。然而，动物生殖系和被子植物配子体发育之间的比较揭示了在细胞学和分子水平上存在许多令人惊讶的相似之处。在植物和动物采用的非常不同的生活策略的背景下，回顾了这种生活史的差异和发育过程的相似性，特别是植物在发育早期不将二倍体生殖系搁置的事实。
