Emergence of the Ug99 lineage of the wheat stem rust pathogen through somatic hybridisation
Emergence of the Ug99 lineage of the wheat stem rust pathogen through somatic hybridisation
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DOI：
10.1038/s41467-019-12927-7
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发表时间：
2019-11-07
影响因子：
16.6
通讯作者：
Figueroa, Melania
中科院分区：
文献类型：
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作者：
Li, Feng;Upadhyaya, Narayana M.;Figueroa, Melania
副性行为有助于单倍体真菌的多样性和适应性进化。然而，在双核真菌（包含两个不同的单倍体核）中，非性遗传交换机制尚未明确。新出现的小麦茎锈病病原菌小麦锈病（Pgt），如Ug99，是对全球粮食安全的重大威胁。在这里，我们提供了基于基因组学的证据，支持Ug99是由体细胞杂交和双核子之间的核交换产生的。完全单倍型解决基因组组装和DNA接近分析表明，Ug99与一个更古老的非洲Pgt谱系共享一个单倍体核基因型，没有重组或染色体重组。这些发现表明，在无性真菌群体中，双核生物之间的核交换可以产生遗传多样性，并促进新世系的出现。
Parasexuality contributes to diversity and adaptive evolution of haploid (monokaryotic) fungi. However, non-sexual genetic exchange mechanisms are not defined in dikaryotic fungi (containing two distinct haploid nuclei). Newly emerged strains of the wheat stem rust pathogen, Puccinia graminis f. sp. tritici (Pgt), such as Ug99, are a major threat to global food security. Here, we provide genomics-based evidence supporting that Ug99 arose by somatic hybridisation and nuclear exchange between dikaryons. Fully haplotype-resolved genome assembly and DNA proximity analysis reveal that Ug99 shares one haploid nucleus genotype with a much older African lineage of Pgt, with no recombination or chromosome reassortment. These findings indicate that nuclear exchange between dikaryotes can generate genetic diversity and facilitate the emergence of new lineages in asexual fungal populations.