Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, 08003, Spain.
Universitat Pompeu Fabra (UPF), 08003, Barcelona, Spain.
BMC Biol. 2018 Jan 25;16(1):15. doi: 10.1186/s12915-018-0482-y.
Polyploidization is one of the major evolutionary processes that shape eukaryotic genomes, being particularly common in plants. Polyploids can arise through direct genome doubling within a species (autopolyploidization) or through the merging of genomes from distinct species after hybridization (allopolyploidization). The relative contribution of both mechanisms in plant evolution is debated. Here we used phylogenomics to dissect the tempo and mode of duplications in the genome of the olive tree (Olea europaea), one of the first domesticated Mediterranean fruit trees.
Our results depict a complex scenario involving at least three past polyploidization events, of which two-at the bases of the family Oleaceae and the tribe Oleeae, respectively-are likely to be the result of ancient allopolyploidization. A more recent polyploidization involves specifically the olive tree and relatives.
Our results show the power of phylogenomics to distinguish between allo- and auto polyploidization events and clarify the contributions of duplications in the evolutionary history of the olive tree.
多倍化是塑造真核生物基因组的主要进化过程之一，在植物中尤为常见。多倍体可以通过物种内的直接基因组加倍（自体多倍化）或杂交后来自不同物种的基因组融合（异源多倍化）而产生。这两种机制在植物进化中的相对贡献仍存在争议。在这里，我们使用系统发生基因组学来剖析橄榄树（Olea europaea）基因组中的重复时间和模式，橄榄树是最早被驯化的地中海果树之一。
我们的结果描绘了一个复杂的情景，其中至少涉及三个过去的多倍化事件，其中两个-分别在木犀科和木犀草科的基部-可能是远古异源多倍化的结果。最近的一次多倍化则涉及到橄榄树及其近亲。
我们的结果表明了系统发生基因组学在区分异源和自体多倍化事件以及阐明在橄榄树进化历史中的重复作用方面的强大功能。
