Abstract Detail

Population Genetics/Genomics

Medrano, Mónica [1], Alonso, Conchita [1], Bazaga, Pilar [1], López, Esmeralda [1], Herrera, Carlos [1].

Comparative genetic and epigenetic diversity in pairs of sympatric, closely-related plants with contrasting distribution ranges in southeastern Iberian mountains.

Genetic diversity defines the evolutionary potential of a species, yet mounting evidence suggests that epigenetic diversity could also contribute to adaptation. Elucidating the complex interplay between genetic and epigenetic variation in wild populations remains a challenge for evolutionary biologists, and the intriguing possibility that epigenetic diversity could compensate for the loss of genetic diversity is one aspect that remains basically unexplored in wild plants. We addressed this hypothesis by comparing the extent and patterns of genetic and epigenetic diversity of phylogenetically closely related but ecologically disparate species. Seven pairs of congeneric species from Cazorla mountains in southeastern Spain were studied, each pair consisting of one endemic, restricted-range species associated to stressful environments, and one widespread species occupying more favorable habitats. The prediction was tested that endemic species should have lower genetic diversity due to population fragmentation, and higher epigenetic diversity induced by environmental stress, than their widespread congeners. Genetic (DNA sequence variants) and epigenetic (DNA cytosine methylation variants) diversities and their possible covariation were assessed in three populations of each focal species using Amplified Fragment Length Polymorphism (AFLP) and Methyl Sensitive AFLP (MSAP). All species and populations exhibited moderate to high levels of genetic polymorphism irrespective of their ecological characteristics. Epigenetic diversity was greater than genetic diversity in all cases. Only in endemic species were the two variables positively related, but the difference between epigenetic and genetic diversity was greater at populations with low genetic polymorphism. Results revealed that the relationship between genetic and epigenetic diversity can be more complex than envisaged by the simple hypothesis initially posed, and highlight the need of additional research on the actual role of epigenetic variation as a source of phenotypic diversity before a realistic understanding of the evolutionary relevance of epigenetic phenomena in plant adaptation can be achieved.

1 - Estacion Biologica de Doñana, CSIC, Evolutionary Ecology, Avda Americo Vespucio 26, Sevilla, E-41092, Spain

DNA methylation
epigenetic diversity
genetic diversity
Mediterranean mountains
population epigenetics.

Presentation Type: Oral Paper
Session: POPGEN1, Population Genetics/Genomics I
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 3:00 PM
Number: POPGEN1001
Abstract ID:200
Candidate for Awards:Margaret Menzel Award

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