Untangling individual variation in natural populations: ecological, genetic and epigenetic correlates of long-term inequality in herbivory
Untangling individual variation in natural populations: ecological, genetic and epigenetic correlates of long-term inequality in herbivory
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DOI：
10.1111/j.1365-294x.2011.05026.x
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发表时间：
2011-04-01
影响因子：
4.9
通讯作者：
Bazaga, P.
中科院分区：
文献类型：
--
作者：
Herrera, C. M.;Bazaga, P.
生物体重要生态特征的个体变异是生态学和进化的关键因素，但在自然种群中很难解开其根本原因。我们应用了基因组扫描方法，使用扩增片段长度多态性（AFLP）标记，以量化的遗传基础的长期个体差异，在野生种群的紫色Viola cazorlensis监测二十年的哺乳动物食草动物。此外，甲基化敏感性扩增多态性（MSAP）分析被用来调查浏览损害和表观遗传特征的个人，一个方面，以前没有探索任何野生植物之间的关联。结构方程模型被用来确定可能的因果结构连接基因型，表观基因型和草食动物。在20年的研究期间，V. cazorlensis的个体在浏览哺乳动物的发病率方面差异很大。6个AFLP标记（占总标记数的1.6%）与植食性显著相关，共解释了44%的群体间植食性变异。MSAP分析显示，相当大的表观遗传变异个体之间，差异浏览损害显着相关的多位点表观基因型的变化。此外，在表观遗传特征的植物之间的变化是相关的几个草食相关的AFLP标记的变化。替代因果模型的统计比较表明，草食动物的个体差异是一个复杂的因果结构的结果，基因型和表观基因型是相互关联的，对草食动物有直接和间接的影响。由于影响植食性的MSAP标记的甲基化状态是可转代遗传的，因此植食性驱动的研究群体的进化变化将涉及基因型和表观基因型分布的相关变化。
Individual variation in ecologically important features of organisms is a crucial element in ecology and evolution, yet disentangling its underlying causes is difficult in natural populations. We applied a genomic scan approach using amplified fragment length polymorphism (AFLP) markers to quantify the genetic basis of long-term individual differences in herbivory by mammals at a wild population of the violet Viola cazorlensis monitored for two decades. In addition, methylation-sensitive amplified polymorphism (MSAP) analyses were used to investigate the association between browsing damage and epigenetic characteristics of individuals, an aspect that has been not previously explored for any wild plant. Structural equation modelling was used to identify likely causal structures linking genotypes, epigenotypes and herbivory. Individuals of V. cazorlensis differed widely in the incidence of browsing mammals over the 20-year study period. Six AFLP markers (1.6% of total) were significantly related to herbivory, accounting altogether for 44% of population-wide variance in herbivory levels. MSAP analyses revealed considerable epigenetic variation among individuals, and differential browsing damage was significantly related to variation in multilocus epigenotypes. In addition, variation across plants in epigenetic characteristics was related to variation in several herbivory-related AFLP markers. Statistical comparison of alternative causal models suggested that individual differences in herbivory are the outcome of a complex causal structure where genotypes and epigenotypes are interconnected and have direct and indirect effects on herbivory. Insofar as methylation states of MSAP markers influential on herbivory are transgenerationally heritable, herbivore-driven evolutionary changes at the study population will involve correlated changes in genotypic and epigenotypic distributions.