ZKS cells are primary kidney stromal cells. (A) Morphologic characterization of ZKS cells. (i,ii) May-Grünwald/Giemsa staining of ZKS cells on glass coverslips reveals stromal morphology. Images in subpanel i were photographed at 100× at 100% confluence; those in subpanel ii were photographed at 400× at low confluence. Transmission electron micrographs of ZKS stromal cells show ultrastructural features of fibroblasts. (iii) Close-up of ZKS cell, 7900×. Note abundant mitochondria and free ribosomes. (iv) Close-up of a ZKS cell, 19 000×. Note abundant Golgi and rough endoplasmic reticular network. n indicates nucleus; g, Golgi; r, ribosome; rER, rough endoplasmic reticulum; ly, lysosome; f, filaments; and m, mitochondria. (B) ZKS cells do not express hematopoietic specific transcripts. Gene expression analysis of ZKS cells by RT-PCR for the pan leukocytic transcript cd45 and erythroid specific gata1. Gene names listed at left. Whole kidney used as positive controls, dH2O as negative controls. (C) Gene expression analysis of ZKS cells by RT-PCR for transcripts involved in proliferation and differentiation of progenitor cells (left column), niche signaling and lymphoid development (middle column), and lineage-specific signaling, maintenance, and differentiation (right column). Gene names listed at left. Whole kidney used as positive controls, dH2O as negative controls.
