The capacity to respond to environmental challenges ultimately relies on phenotypic variation which manifests from complex interactions of genetic and nongenetic mechanisms through development. While we know something about genetic variation and structure of many species of conservation importance, we know very little about the nongenetic 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 anthropogenic environmental changes. Several studies have documented landscape-level patterns of genetic variation in this species, but we know virtually nothing about the inheritance of nongenetic variation. To assess one type of nongenetic 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; 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. In addition, 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：

---

红树林红树根中DNA甲基化差异的遗传

应对环境挑战的能力最终依赖于表型变异，表型变异表现为遗传和非遗传机制通过发育的复杂相互作用。虽然我们对许多具有保护重要性的物种的遗传变异和结构有所了解，但我们对非遗传对变异的贡献知之甚少。根瘤菌是一种基础物种，出现在整个新热带地区的沿海河口栖息地，在那里它提供关键的生态系统功能，并可能受到人为环境变化的威胁。几项研究已经记录了该物种遗传变异的景观水平模式，但我们对非遗传变异的遗传几乎一无所知。为了评估一种类型的非遗传变异，我们检查了来自佛罗里达州墨西哥湾沿岸的R. mangle自然种群的母本植物和后代的 DNA 序列和 DNA 甲基化模式。我们使用减少代表性的亚硫酸氢盐测序方法（通过测序进行表观基因分型；epiGBS）来解决以下问题：R. mangle ? (b) 种群内部和种群之间的遗传和表观遗传变异是如何构成的？(c) 表观遗传变异的遗传程度如何？我们从田间母本植物的自然种群中发现低遗传多样性但高表观遗传多样性。此外，在普通花园中生长的后代中，很大一部分（高达~25%）的表观遗传差异是由母系解释的。因此，表观遗传变异可能是对这一基础物种的遗传衰退种群中具有挑战性的环境做出反应的重要来源。