Papilla dissected from one kidney or piece of ventricle removed from heart. Tissue incubated overnight at 4 oC[EP12.1] in RNAlater (Invitrogen AM7020). Tissue was transferred to lysis buffer, stored at -70 oC, lysed with two freeze-thaw cycles and disrupted manually with forceps. Samples were centrifuged (12.1 rcf, 2 min) and the supernatant passed through an 18-gauge needle.   Total RNA was isolated using a PureLink RNA Mini kit (Invitrogen #12183018A).   For RNAseq the samples were treated with DNase I. RNA integrity was checked using a 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA), and concentrations were measured using the NanoDrop system (Thermo Fisher Scientific, Inc., Waltham, MA). Preparation of RNA sample library and RNA-seq were performed by the Genomics Core Laboratory at Weill Cornell Medicine. Messenger RNA was prepared using TruSeq Stranded mRNA Sample Library Preparation kit (Illumina, San Diego, CA), according to the manufacturer's instructions. The normalized cDNA libraries were pooled and sequenced on Illumina NovaSeq X plus sequencer with single-end 50 cycles.