Endosperm-based incompatibilities in hybrid monkeyflowers
Endosperm-based incompatibilities in hybrid monkeyflowers
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DOI：
10.1093/plcell/koab117
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发表时间：
2021-04-25
期刊：
影响因子：
11.6
通讯作者：
Puzey, Joshua R.
中科院分区：
文献类型：
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作者：
Kinser, Taliesin J.;Smith, Ronald D.;Puzey, Joshua R.
胚乳是被子植物繁殖的核心，其发育和种子活力受基因组印记控制，其中某些基因的表达是亲本特异性的。不成功的印记已被链接到失败的种间和倍性间杂交。尽管它们在植物物种形成中的重要性，但这些基于胚乳的障碍背后的潜在机制仍然知之甚少。在这里，我们描述了一个这样的障碍之间的二倍体Mimulus guttatus和四倍体Mimulus luteus。两个亲本在胚乳DNA甲基化、表达动态和印记基因方面存在差异。杂种种子胚乳发育不全，生活力降低，或胚乳停滞，种子败育。guttatus或M. luteus分别是种子亲本，并且出现超亲甲基化和表达模式。两人继承了M。黄体亚基因组，遗传上不同，但表观遗传相似，表现为显性的M。guttatus基因组中的杂种胚胎，特别是他们的胚乳，其中父亲的印记被扰乱。在败育种子中，从头甲基化被抑制，可能是由于来自M.点滴印记我们认为，父母的基因组之间的表观遗传/监管景观分化诱导表观遗传的再模式化和全球的表达，这在胚乳中，可能会独特地促进不同的印记方案之间的不相容的相互作用，潜在的驱动快速的障碍。
Endosperm is an angiosperm innovation central to their reproduction whose development, and thus seed viability, is controlled by genomic imprinting, where expression from certain genes is parent-specific. Unsuccessful imprinting has been linked to failed inter-specific and inter-ploidy hybridization. Despite their importance in plant speciation, the underlying mechanisms behind these endosperm-based barriers remain poorly understood. Here, we describe one such barrier between diploid Mimulus guttatus and tetraploid Mimulus luteus. The two parents differ in endosperm DNA methylation, expression dynamics, and imprinted genes. Hybrid seeds suffer from underdeveloped endosperm, reducing viability, or arrested endosperm and seed abortion when M. guttatus or M. luteus is seed parent, respectively, and transgressive methylation and expression patterns emerge. The two inherited M. luteus subgenomes, genetically distinct but epigenetically similar, are expressionally dominant over the M. guttatus genome in hybrid embryos and especially their endosperm, where paternal imprints are perturbed. In aborted seeds, de novo methylation is inhibited, potentially owing to incompatible paternal instructions of imbalanced dosage from M. guttatus imprints. We suggest that diverged epigenetic/regulatory landscapes between parental genomes induce epigenetic repatterning and global shifts in expression, which, in endosperm, may uniquely facilitate incompatible interactions between divergent imprinting schemes, potentially driving rapid barriers.