Molecular detection of maturation stages in the developing kidney

To identify maturation-dependent genes, we here performed single cell RNA sequencing (scRNA-seq) analysis using developing kidneys at different stages in the mouse, followed by highly sensitive in situ hybridization. We identified multiple genes expressed abundantly in newborn kidneys, but minimally at embryonic day 15.5. We then applied these maturation markers to the transplanted embryonic kidneys and found that the maturation process did not occur equally throughout nephron segments upon transplantation: glomeruli and proximal renal tubules became more mature than the other nephron segments. Thus, our scRNA-seq data at multiple stages of kidney development and identified maturation-dependent genes will serve as useful bases for assessing maturation of the developing kidney, and eventually of kidney organoids. Overall design: Kidney mRNA profiles of embryonic day 15.5, 17.5 and postnatal day 0 mice were generated by deep sequencing, using Illumina 10x E12.5 embryonic kidneys were transplanted into the epididymis fat of NOD immuno deficient mice for 12 days