| 植物多倍体基因组的形成与进化 |
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| 引用本文： | 杨继.植物多倍体基因组的形成与进化[J].中国科学院研究生院学报,2001,39(4):357-372. |
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| 作者姓名： | 杨继 |
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| 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。
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| 关 键 词： | 多倍体植物 多元发生 基因组进化 |
The formation and evolution of polyploid genomes in plants |
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| YANG Ji.The formation and evolution of polyploid genomes in plants[J].Journal of the Graduate School of the Chinese Academy of Sciences,2001,39(4):357-372. |
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| Authors: | YANG Ji |
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| Abstract: | 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 per-
spectives have enhanced our awareness of the myriad genetic interactions made possible by
polyploidy. In this paper, cytological mechanisms of polyploid formation and processes and mecha-
nisms 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 differ-
ent populations of their progenitors. Genes duplicated by polyploidy may retain their original or simi-
lar function, undergo diversification in protein function or regulation, or one copy may become si-
lenced through mutational or epigenetic means. Duplicated genes also may interact through inter-lo-
cus recombination, gene conversion, or concerted evolution. Extensive and rapid genome restructur-
ing can occur after polyploidization. These include inter-genomic chromosomal exchanges, non-Men-
delian genomic evolution in nascent polyploids, inter-genomic invasion, and cytonuclear stabiliza-
tion. Continued application of molecular genetic approaches to questions of polyploid genome evolu-
tion holds promise for producing lasting insight into processes by which novel genotypes are generatedand ultimately into how polyploidy facilitates evolution and adaptation. |
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| Keywords: | Polyploid plants Multiple origins Genome evolution |
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