Project description:The OK cell line derived from kidney of a female opossum Didelphys virginiana has proven to be a useful model in which to investigate the unique regulation of ion transport and membrane trafficking mechanisms in the proximal tubule (PT). Sequence data and comparison of the transcriptome of this cell line to eutherian mammal PTs would further broaden the utility of this culture model. However, genomic sequence for Didelphys virginiana is not available and although a draft genome sequence for the opossum Monodelphis domestica (sequenced in 2012 by the Broad Institute) exists, its relatedness and similarity of the transcriptome to the Didelphys virginiana species is not known. The Monodelphis domestica sequence is not highly annotated, and the majority of transcripts are predicted rather than experimentally validated. Using deep RNA sequencing of the Didelphys virginiana OK cell line we characterized its transcriptome using de novo transcriptome assembly and alignment to the Monodelphis domestica genome. The quality of the de novo assembled transcriptome was assessed by the extent of homology to sequences in nucleotide and protein databases. Gene expression levels in the OK cell line, from both the de novo transcriptome and genes aligned to the Monodelphis domestica genome, were compared to publicly available rat kidney nephron segment expression data. Our studies demonstrate the expression in OK cells of numerous PT specific ion transporters and other key proteins relevant for rodent and human PT function. The sequence and expression data reported here provide a new and important resource for studies on the regulation of PT mRNA and protein expression.