Most reptiles lay eggs in sand or soil, under logs or in rock crevices. These are places where the temperature often fluctuates, sometimes becoming dangerously high or low. The pervasive effects of temperature on biological systems begs the question how embryos respond in the short term, and how populations adapt in the long term. This question is now thoroughly explored in a theme issue of the Journal of Experimental Zoology, with contributions from our group.

In a study on wall lizards led by Nathalie Feiner, we reveal a pervasive effect of temperature on gene expression in early embryos. The strongest responses were found for genes involved in transcriptional and translational regulation and chromatin remodelling, suggesting possible epigenetic mechanisms underlying thermal acclimation. In another paper, ploughing through 50 years of experimental studies, Dan Noble, Geoff While, and colleagues summarize research on thermal plasticity in reptile embryos, and demonstrate how future progress can be made through meta-analytic and comparative work. The data are accessible to everyone through a paper in the journal Scientific Data, and can be downloaded through this online data base. More papers in this special issue are available through the Journal of Experimental Zoology online early.