Epigenetic phenomena and the evolution of plant allopolyploids  

作　　者：BaoLiu JonathanF.Wendel 

机构地区：[1]InstituteofGeneticsandCytology,NortheastNormalUnit,ersity.Cliangchun130024,China [2]DepartmentofBotany,353BesseyHall,IowaStateUniversity.Ames,IA50011.USA

出　　处：《中国生物学文摘》2005年第4期8-22,共15页Chinese Biological Abstracts

摘　　要：Allopolyploid speciation is widespread in plants, yet the molecular requirements for successful orchestration of coordinated gene expression for two divergent and reunited genomes are poorly understood. Recent studies in several plant systems have revealed that allopolyploid genesis under both synthetic and natural conditions often is accompanied by rapid and sometimes evolutionarily conserved epigeuetic changes, including alteration in cytosine methylation patterns, rapid silencing in ribosomal RNA and proteincoding genes, and de-repression of dormant transposable elements. These changes are inter-related and likely arise from chromatin remodeling and its effects on epigenetic codes during and subsequent to allopolyploid formation. Epigenetic modifications could produce adaptive epimutations and novel phenotypes, some of which may be evolutionarily stable for millions of years, thereby representing a vast reservoir of latent variation that may be episodically released and made visible to selection. This epigenetic variation may contribute to several important attributes of allopolyploidy, including functional diversification or subfunctionalization of duplicated genes, genetic and cytological diploidization, and quenching of incompatible inter-genomic interactions that are characteristic of allopolyploids. It is likely that the evolutionary success of allopolyploidy is in part attributatble to epigenetic phenomena that we are only just beginning to understand.

关 键 词：植物 异源多倍性 基因组 进化 DNA甲基化 基因抑制 转位因子 发育遗传学 

分 类 号：Q943[生物学—植物学]