The three objectives outlined above map onto three independent work packages that have distinct methodologies, challenges and objectives. WP1 (comparative developmental biology) uses sophisticated cell sorting combined with transcriptome and methylome analyses to reveal if independent origins of the syndrome share the same modifications of NCCs. WP2 (evolutionary genomics) applies exhaustive genome sequencing across the entire Podarcis genus to establish how the parallelism at the phenotypic level is mirrored at the genomic level. WP3 (experimental developmental biology) includes gene editing to target a mechanistic dissection of developmental pathways and a reconstruction of the likely evolutionary steps at the origin of the syndrome.
During the first 30 month of the project, the team working with the EvoOnRepeat project has achieved several milestones. Regarding WP1, the establishment of a novel methodology that allows sorting of neural crest cells in wall lizard embryos was identified as a high-risk element, but most obstacles have been overcome thanks to our dedicated efforts towards this methodological innovation. For three consecutive years, my team has collected a large number of lizards eggs (> 500 per year) and collaborated with a biomedical center and the eukaryotic single cell genomics center (both in Sweden), to improve and fine-tune the methodology. Thanks to these achievements, we are now in a position to launch the main experiment, which will inform us on differences in the transcriptomic state of neural crest cells in lizard lineages with and without the syndrome phenotype. Similarly, WP2 has proceeded largely according to our initial plans. A core element of WP2 is the sampling of lizards in the wild. Despite that the first field season (2021) could not be conducted as planned due to Covid19-related travel restrictions, we have conducted two highly successful field expeditions in 2022 and 2023. We have successfully sampled eight wall lizard species, and thanks to our newly developed phenotyping protocol, we have collected highly informative multivariate data at an unprecedented resolution. Analyses of phenotypic and genomic data are currently ongoing, and one major publication is currently under review. Regarding WP3, initial failure to recruit a suitable postdoc has paused this part of the project. However, a new attempt to attract a suitable co-worker are currently underway.
