Genome-wide identification of regeneration enhancer for nephric tubules using ATAC-seq and in vivo enhancer mapping

During tissue regeneration, cells first detect damage and then change the transcriptional status in their nuclei to reconstruct the tissue. Previous studies have been revealed that the molecular basis behind regeneration, and found that many developmental genes are reused during regeneration. Therefore, the mechanisms that control the expression of developmental genes after injury are key to understanding the molecular basis of regeneration. However, only a few enhancers that contribute to regeneration have been reported. This is because developmental enhancers can be readily determined by examining reporter gene expression at the developmental stage of interest. In contrast, regeneration enhancers are inactive in uninjured tissues, and the confirmation of injury/regeneration-response activities of candidate enhancers requires the creation of transgenic reporter animals and an additional regeneration assay. Recently, we established the simple method for validation of in vivo regeneration activities using a Xenopus laevis transgenic system, and found the responsible enhancers named regeneration signal-response enhancers for Lhx1. In this project, we will first identify open chromatin regions in regenerating nephric tubule using ATAC-seq, and then validate the regeneration enhancer activities of open chromatin regions using the Xenopus laevis transgenic system. Based on this combinational approach using both narrowing down of putative enhancer utilizing ATAC-seq and the transgenic analysis, we will discover the molecular basis behind regeneration enhancers.