title: Epigenetic regulation of sex ratios may explain natural variation in self-fertilization rates.
abstract: Self-fertilization (selfing) favours reproductive success when mate availability is low, but renders populations more vulnerable to environmental change by reducing genetic variability. A mixed-breeding strategy (alternating selfing and outcrossing) may allow species to balance these needs, but requires a system for regulating sexual identity. We explored the role of DNA methylation as a regulatory system for sex-ratio modulation in the mixed-mating fish Kryptolebias marmoratus. We found a significant interaction between sexual identity (male or hermaphrodite), temperature and methylation patterns when two selfing lines were exposed to different temperatures during development. We also identified several genes differentially methylated in males and hermaphrodites that represent candidates for the temperature-mediated sex regulation in K. marmoratus. We conclude that an epigenetic mechanism regulated by temperature modulates sexual identity in this selfing species, providing a potentially widespread mechanism by which environmental change may influence selfing rates. We also suggest that K. marmoratus, with naturally inbred populations, represents a good vertebrate model for epigenetic studies.
authors.affiliation: IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK.
authors.forename: Amy
authors.initials: A
authors.lastname: Ellison
authors.affiliation: School of Agriculture, Wine and Food, University of Adelaide, Adelaide 5005, Australia.
authors.forename: Carlos Marcelino
authors.initials: CM
authors.lastname: Rodríguez López
authors.affiliation: Facultad de Biología, Universidad de Vigo, Vigo 36310, Spain.
authors.forename: Paloma
authors.initials: P
authors.lastname: Moran
authors.affiliation: School of Agriculture, Wine and Food, University of Adelaide, Adelaide 5005, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Breen
authors.affiliation: IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Swain
authors.affiliation: Facultad de Biología, Universidad de Vigo, Vigo 36310, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Megias
authors.affiliation: IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Hegarty
authors.affiliation: School of Agriculture, Wine and Food, University of Adelaide, Adelaide 5005, Australia.
authors.forename: Mike
authors.initials: M
authors.lastname: Wilkinson
authors.affiliation: Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Pawluk
authors.affiliation: IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK s.consuegra@swansea.ac.uk.
authors.forename: Sofia
authors.initials: S
authors.lastname: Consuegra
mesh_terms: D000818:Animals; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D057850:Hermaphroditic Organisms / Q000235:genetics / Q000502:physiology; D007695:Killifishes / Q000235:genetics / Q000502:physiology*; D008297:Male; D057945:Self-Fertilization; D017422:Sequence Analysis, DNA; D012744:Sex Ratio; D012726:Sexual Behavior, Animal; D013696:Temperature
keywords: DNA methylation; inbreeding; mangrove killifish; mate availability; mixed mating; selfing