The capacity to respond to environmental challenges ultimately relies on phenotypic variation which manifests from complex interactions of genetic and non-genetic mechanisms through development. While we know something about genetic variation and structure of many species of conservation importance, we know very little about the non-genetic contributions to variation. Rhizophora mangle is a foundation species that occurs in coastal estuarine habitats throughout the neotropics where it provides critical ecosystem functions, and is potentially threatened by climate change. Several studies have documented landscape level patterns of genetic variation in this species, but we know virtually nothing about the inheritance of non-genetic variation. To assess one type of non-genetic variation, we examined the patterns of DNA sequence and DNA methylation in maternal plants and offspring from natural populations of R. mangle from the Gulf Coast of Florida. We used a reduced representation bisulfite sequencing approach (epi-genotyping by sequencing or epiGBS) to address the following questions: a) What are the levels of genetic and epigenetic diversity in natural populations of R. mangle? b) How are genetic and epigenetic variation structured within and among populations? c) How faithfully is epigenetic variation inherited? We found low genetic diversity but high epigenetic diversity from natural populations of maternal plants in the field and that a large portion (up to ~25%) of epigenetic differences among offspring grown in common garden was explained by maternal family. Therefore, epigenetic variation could be an important source of response to challenging environments in the genetically depauperate populations of this foundation species.

中文翻译：

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红树林Rhizophora Mangle中DNA甲基化差异的遗传

应对环境挑战的能力最终取决于表型变异，这种变异表现为遗传和非遗传机制通过发育的复杂相互作用。尽管我们对许多具有重要保护意义的物种的遗传变异和结构有所了解，但对变异的非遗传贡献却知之甚少。根瘤菌是基础物种，存在于整个新热带地区的沿海河口栖息地，在这里提供关键的生态系统功能，并可能受到气候变化的威胁。几项研究已记录了该物种遗传变异的景观水平格局，但我们几乎对非遗传变异的遗传一无所知。为了评估一种类型的非遗传变异，我们检查了佛罗里达州墨西哥湾沿岸天然红唇。鱼自然种群的母本植物和后代中DNA序列和DNA甲基化的模式。我们使用了精简表示亚硫酸氢盐测序方法（通过测序或epiGBS外延基因分型），以解决以下问题：1）什么是遗传和表观遗传多样性的自然种群的水平R.撕裂？b）种群内部和种群之间的遗传和表观遗传变异如何构成？c）表观遗传变异是如何忠实地遗传的？我们从田间母本植物的自然种群中发现了较低的遗传多样性，但表观遗传的多样性很高，母本家庭解释了在共同花园中生长的后代之间很大一部分（高达约25％）的表观遗传差异。因此，表观遗传变异可能是该基础物种在遗传上绝育种群中应对挑战性环境的重要来源。