Ultrastructure of the renal corpuscle of the garter snake Thamnophis sirtalis.

The renal corpuscle of the garter snake was examined using scanning and transmission electron microscopy, freeze-fracture and tracer experiments. The renal corpuscle was small and glomerular architecture simple. The visceral epithelium was composed of irregular, highly branched podocytes with broad, interdigitating foot processes. Numerous cell junctions, including fasciae occludentes and adhaerentes, occurred between podocytes. The podocytes bore numerous microvilli which projected into the urinary space and contained large bundles of microfilaments. The podocytes lay on a basal lamina which appeared to act as a primary filtration barrier.