Signatures of selection in embryonic transcriptomes of lizards adapting in parallel to cool climate

Journal article

Populations adapting independently to the same environment provide important insights into the repeatability of evolution at different levels of biological organization. In the 20th century, common wall lizards (Podarcis muralis) from southern and western Europe were introduced to England, north of their native range. Non-native populations of both lineages have adapted to the shorter season and lower egg incubation temperature by increasing the absolute rate of embryonic development. Here we tested if this adaptation is accompanied by signatures of directional selection in the transcriptomes of early embryos and, if so, if non-native populations show adaptive convergence. Embryos from non-native populations exhibited gene expression profiles consistent with directional selection following introduction, but different genes were affected in the two lineages. Despite this, the functional enrichment of genes that changed their expression following introduction showed substantial similarity between lineages, and was consistent with mechanisms that should promote developmental rate. Moreover, the divergence between non-native and native populations was enriched for genes that were temperature- responsive in native populations. These results indicate that small populations are able to adapt to new climatic regimes, but the means by which they do so may largely be determined by founder effects and other sources of genetic drift.

Authors: Feiner, N; Rago, A; While, G; Uller, O

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Society for the Study of Evolution
• Journal: Evolution
• Volume: 72
• Issue: 1
• Pages: 67–81
• Publication date: 2017-12-06
• Acceptance date: 2017-11-04
• DOI: 10.1111/evo.13397
• EISSN: 1558-5646
• ISSN: 0014-3820
• Keywords: convergent evolution; transcriptomics; thermal adaptation; climate; lizard; non-native