Two Evolutionarily Distinct Classes of Paleopolyploidy
Two Evolutionarily Distinct Classes of Paleopolyploidy
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DOI：
10.1093/molbev/mst230
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发表时间：
2014-02-01
影响因子：
10.7
通讯作者：
Freeling, Michael
中科院分区：
文献类型：
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作者：
Garsmeur, Olivier;Schnable, James C.;Freeling, Michael
全基因组重复（WGD）发生在许多谱系的遥远进化历史中，特别是在显花植物谱系中。在植物的古多倍化之后，大多数重复的基因通过染色体内重组被删除，这一过程被称为分离。在迄今为止研究的例子中，基因不成比例地从亲本亚基因组中丢失（偏倚分馏），并且丢失最少数量基因的亚基因组更多地表达（基因组显性）。在本研究中，我们分析了香蕉最近的WGD（α事件）后的基因缺失和基因表达模式，并将我们的分析扩展到其他七种测序植物基因组：白杨，大豆，苜蓿，拟南芥，高粱，芸苔属和玉米。我们提出了一类新的古老的WGD，与芭蕉（阿尔法），白杨，大豆作为成员，基因都删除和表达到同等程度（无偏分馏和基因组等效）。我们认为具有基因组优势和偏向分离的WGD（I类）可能来自古老的异源四倍体，而没有基因组优势或偏向分离的WGD（II类）可能来自古老的同源四倍体。
Whole genome duplications (WGDs) occurred in the distant evolutionary history of many lineages and are particularly frequent in the flowering plant lineages. Following paleopolyploidization in plants, most duplicated genes are deleted by intrachromosomal recombination, a process referred to as fractionation. In the examples studied so far, genes are disproportionately lost from one of the parental subgenomes (biased fractionation) and the subgenome having lost the lowest number of genes is more expressed (genome dominance). In the present study, we analyzed the pattern of gene deletion and gene expression following the most recent WGD in banana (alpha event) and extended our analyses to seven other sequenced plant genomes: poplar, soybean, medicago, arabidopsis, sorghum, brassica, and maize. We propose a new class of ancient WGD, with Musa (alpha), poplar, and soybean as members, where genes are both deleted and expressed to an equal extent (unbiased fractionation and genome equivalence). We suggest that WGDs with genome dominance and biased fractionation (Class I) may result from ancient allotetraploidies, while WGDs without genome dominance or biased fractionation (Class II) may result from ancient autotetraploidies.