Epigenetic Mapping of Cis-Regulatory Elements in the Developing Mouse and Pig Forelimbs.

Cis-regulatory elements (CREs) orchestrate the spatio-temporal regulation of key transcriptional programs. These elements - including promoters, enhancers, and insulators - play a crucial role in embryonic development and in morphological evolution. We performed ChIP-seq for histone modifications (H3K4me3, H3K27ac, and H3K4me1) from equivalent stages of mouse (E11.5) and pig (day 23; D23) forelimb development to catalog the limb bud regulome in both species. The overlap of these epigenomic signatures with the pattern of open chromatin during limb development previously described for both species allowed us to classify these putative regulatory regions into different chromatin states. Our studies offer a valuable resource in the evo-devo field for exploring mechanisms underlying the morphological evolution of the tetrapod limb.