植物多倍体基因组的形成与进化  

The formation and evolution of polyploid genomes in plants

作　　者：杨继[1] 

机构地区：[1]北京大学生命科学学院,北京100871

出　　处：《植物分类学报》2001年第4期357-371,共15页Acta Phytotaxonomica Sinica

基　　金：国家重点基础研究发展规划项目 (G2 0 0 0 0 4 680 4 );国家自然科学基金项目 (3 9970 0 5 1 )

摘　　要：多倍化是植物进化变异的自然现象 ,也是促进植物发生进化改变的重要力量。在被子植物中 ,约70 %的种类在进化史中曾发生过一次或多次多倍化的过程。目前的研究结果表明 ,自然界绝大多数多倍体是通过未减数配子的融合而形成的 ,并且很多多倍体种是通过多次独立的多倍化过程而重复发生的。由多倍化所导致的重复基因在多倍体基因组中可能有三种不同的命运 ,即 :保持原有的功能、基因沉默或分化并执行新的功能。多倍化以后 ,重复基因组的进化动态则主要表现在染色体重排和“染色体二倍化”、不同基因组之间的相互渗透、以及核 质之间的相互作用等方面。Polyploidy is widely acknowledged as a major mechanism of adaptation and speciation in plants. Recent estimates suggest that 70% of all angiosperms have experienced one or more episodes of polyploidization. Interdisciplinary approaches combining phylogenetic and molecular genetic perspectives have enhanced our awareness of the myriad genetic interactions made possible by polyploidy. In this paper, cytological mechanisms of polyploid formation and processes and mechanisms of gene and genome evolution in polyploids are reviewed. In many cases, spontaneous polyploids have cytotypes that appear to have been formed by the union of reduced and unreduced gametes. Recent studies demonstrate that most polyploid species have formed recurrently from different populations of their progenitors. Genes duplicated by polyploidy may retain their original or similar function, undergo diversification in protein function or regulation, or one copy may become silenced through mutational or epigenetic means. Duplicated genes also may interact through inter locus recombination, gene conversion, or concerted evolution. Extensive and rapid genome restructuring can occur after polyploidization. These include inter genomic chromosomal exchanges, non Mendelian genomic evolution in nascent polyploids, inter genomic invasion, and cytonuclear stabilization. Continued application of molecular genetic approaches to questions of polyploid genome evolution holds promise for producing lasting insight into processes by which novel genotypes are generated and ultimately into how polyploidy facilitates evolution and adaptation.

关 键 词：多倍体植物 多元发生 基因组进化 

分 类 号：Q943[生物学—植物学]