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Research article - Peer-reviewed, 2021

Ecological adaptation in European eels is based on phenotypic plasticity

Enbody, Erik D.; Pettersson, Mats E.; Sprehn, C. Grace; Palm, Stefan; Wickstrom, Hakan; Andersson, Leif

Abstract

The relative role of genetic adaptation and phenotypic plasticity is of fundamental importance in evolutionary ecology [M. J. West-Eberhard, Proc. Natl. Acad. Sci. U.S.A. 102 (suppl. 1), 6543-6549 (2005)]. European eels have a complex life cycle, including transitions between life stages across ecological conditions in the Sargasso Sea, where spawning occurs, and those in brackish and freshwater bodies from northern Europe to northern Africa. Whether continental eel populations consist of locally adapted and genetically distinct populations or comprise a single panmictic population has received conflicting support. Here we use whole-genome sequencing and show that European eels belong to one panmictic population. A complete lack of geographical genetic differentiation is demonstrated. We postulate that this is possible because the most critical life stages-spawning and embryonic development-take place under near-identical conditions in the Sargasso Sea. We further show that within-generation selection, which has recently been proposed as a mechanism for genetic adaptation in eels, can only marginally change allele frequencies between cohorts of eels from different geographic regions. Our results strongly indicate plasticity as the predominant mechanism for how eels respond to diverse environmental conditions during postlarval stages, ultimately solving a long-standing question for a classically enigmatic species.

Keywords

adaptation; panmixia; plasticity; genome biology

Published in

Proceedings of the National Academy of Sciences of the United States of America
2021, volume: 118, number: 4, article number: e2022620118
Publisher: NATL ACAD SCIENCES

Authors' information

Enbody, Erik D.
Uppsala University
Pettersson, Mats E.
Uppsala University
Sprehn, C. Grace
Uppsala University
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Swedish University of Agricultural Sciences, Department of Aquatic Resources
Andersson, Leif
Uppsala University
Andersson, Leif
Texas A&M University
Andersson, Leif
Swedish University of Agricultural Sciences, Department of Animal Breeding and Genetics

UKÄ Subject classification

Evolutionary Biology

Publication Identifiers

DOI: https://doi.org/10.1073/pnas.2022620118

URI (permanent link to this page)

https://res.slu.se/id/publ/111069