Eichten Steven R, Srivastava Akanksha, Reddiex Adam J, Ganguly Diep R, Heussler Alison, Streich Jared C, Wilson Pip B, Borevitz Justin O
Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Australian National University, Canberra, Acton, Australian Capital Territory 2601, Australia.
Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Australian National University, Canberra, Acton, Australian Capital Territory 2601, Australia
G3 (Bethesda). 2020 May 4;10(5):1629-1637. doi: 10.1534/g3.120.401189.
Epigenomic changes have been considered a potential missing link underlying phenotypic variation in quantitative traits but is potentially confounded with the underlying DNA sequence variation. Although the concept of epigenetic inheritance has been discussed in depth, there have been few studies attempting to directly dissect the amount of epigenomic variation within inbred natural populations while also accounting for genetic diversity. By using known genetic relationships between lines, multiple sets of nearly identical accession families were selected for phenotypic studies and DNA methylome profiling to investigate the dual role of (epi)genetics under simulated natural seasonal climate conditions. Despite reduced genetic diversity, appreciable phenotypic variation was still observable in the measured traits (height, leaf width and length, tiller count, flowering time, ear count) between as well as within the inbred accessions. However, with reduced genetic diversity there was diminished variation in DNA methylation within families. Mixed-effects linear modeling revealed large genetic differences between families and a minor contribution of DNA methylation variation on phenotypic variation in select traits. Taken together, this analysis suggests a limited but significant contribution of DNA methylation toward heritable phenotypic variation relative to genetic differences.
表观基因组变化被认为是数量性状表型变异背后潜在的缺失环节，但可能与潜在的DNA序列变异相互混淆。尽管表观遗传继承的概念已被深入讨论，但很少有研究试图直接剖析近交自然种群内表观基因组变异的数量，同时考虑遗传多样性。通过利用品系间已知的遗传关系，选择多组近乎相同的种质家系进行表型研究和DNA甲基化组分析，以研究在模拟自然季节气候条件下（表观）遗传学的双重作用。尽管遗传多样性降低，但在近交种质之间以及内部，所测量的性状（株高、叶宽和叶长、分蘖数、开花时间、穗数）仍可观察到明显的表型变异。然而，随着遗传多样性的降低，家系内DNA甲基化的变异也减少。混合效应线性模型显示家系间存在较大的遗传差异，DNA甲基化变异对某些性状表型变异的贡献较小。综合来看，该分析表明，相对于遗传差异，DNA甲基化对可遗传表型变异的贡献有限但显著。
