Green, yellow or black? Genetic differentiation and adaptation signatures in a highly migratory marine turtle
Marine species may exhibit genetic structure accompanied by phenotypic differentiation related to adaptation despite their high mobility. The genetic differentiation between green turtle (Chelonia mydas) Pacific shape-based morphotypes (south-central/western or yellow turtle and north-central/eastern or black turtle) and the adaptation of the black turtle to environmentally contrasting conditions of the Eastern Pacific region have remained a mystery for decades. Here we addressed both questions using a reduced-representation genome approach (Dartseq; 9,473 neutral SNPs) and identifying candidate outlier loci (67 outlier SNPs) of biological relevance between shape-based morphotypes from eight Pacific foraging grounds (n=158). Our results support genetic divergence between morphotypes, probably arising from strong natal homing behavior. Genes and enriched biological functions linked to thermoregulation, hypoxia, melanism, morphogenesis,osmoregulation, diet and reproduction were found to be outliers for differentiation, providing evidence for adaptation of C. mydas to the eastern Pacific region and suggesting independent evolutionary trajectories of the shape-based morphotypes. Our findings support the evolutionary distinctness of the enigmatic black turtle (north-central/eastern morphotype) and provide a framework for adaptive research and conservation genomics in long-lived and highly mobile vertebrates.
| Main Authors: | , , , , , , , , , , , , , , , |
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| Published: |
Repositorio de datos de investigación de la Universidad de Chile
2021
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| Subjects: | Earth and Environmental Sciences, Chelonia mydas, genetic structure, candidate genes, melanism, Eastern Pacific, conservation genomics, |
| Online Access: | https://doi.org/10.34691/FK2/RJZUFC |
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