Localization of collagen types IV and V, laminin, and heparan sulfate proteoglycan to the basal lamina of kidney epithelial cells in transfilter metanephric culture.

Mouse metanephric mesenchyme and embryonic spinal cord were cultured on opposite sides of a filter membrane. This resulted in formation of prenephronic vesicles after 36 hours in culture, S-shaped bodies after 2-3 days, and glomeruli and tubules after 4-7 days. The glomeruli consisted of an arborizing tuft of podocytes lying on a basement membrane without vascularization or a mesangial ingrowth. We have used antibodies to study the molecular composition of the nephron basement membrane at each stage of development. By immunofluorescence light microscopy, collagen Types IV and V, laminin, and heparin sulfate proteoglycan were expressed within the pericellular/intercellular matrix at the onset of morphologic differentiation. The molecules were organized into a linear basement membrane associated with epithelial cells during the prenephronic vesicle, S-shaped body, and glomerulus and tubule stages of development.