Fig. 1

Generating a knock-in mouse model with the cetacean HLEA enhancer and performing genotype identification. A Cas9, gRNA and homologous recombination vector were co-injected into C57BL/6J zygotes using the CRISPR/Cas9 system. B Based on PCR amplification and sequencing, the complete cetacean HLEA and four specific deletions were successfully identified in the HKM genome. C CUT&Tag demonstrated that the cetacean HLEA functions as an enhancer in mice (H3K27ac and H3K4me1, which are closely related to enhancer activity, were selected for CUT&Tag experiments. Left: WT, right: HKM). D The enrichment ratios of H3K27ac and H3K4me1 at the HLEA locus in the genomes of WT and HKM were calculated based on the DESeq analysis principles (details are provided in Methods section and Table S1)