Chromatin accessibility and microRNA expression in nephron progenitor cells during kidney development

Mammalian nephrons originate from a population of nephron progenitor cells (NPCs), and it is known that NPCs’ transcriptomes change throughout nephrogenesis during healthy kidney development. To characterize chromatin accessibility and microRNA (miRNA) expression throughout this process, we collected NPCs from mouse kidneys at embryonic day 14.5 (E14.5) and postnatal day zero (P0) and assayed cells for transposase-accessible chromatin and small RNA expression. We observe 46,374 genomic regions of accessible chromatin, with 2,103 showing significant changes in accessibility between E14.5 and P0. In addition, we detect 1,104 known microRNAs, with 114 showing significant changes in expression. Genome-wide, changes in DNA accessibility and microRNA expression highlight biological processes like cellular differentiation, cell migration, extracellular matrix interactions, and developmental signaling pathways such as Notch. Furthermore, our data identify novel candidate cis-regulatory elements for Eya1 and Pax8, both genes with a role in NPC differentiation; we also associate expression-changing microRNAs, including let-7-5p, miR-125b-5p, miR-181a-2-3p, and miR-9-3p, with candidate cis-regulatory elements. Overall, our data characterize NPCs during kidney development and point out new candidate regulatory elements for genes and microRNA with key roles in nephrogenesis.