Morphogenesis of human placental chorionic villi: cytoskeletal, syncytioskeletal and extracellular matrix proteins

Immunocytochemical and ultrastructural methods were used to investigate the distribution of a family of structural proteins in the human placenta near term. These reveal the distribution of cytoskeletal and ‘syncytioskeletal’ components that may account for some of the more obvious micromorphological features of placental structure. In the syncytiotrophoblast a potentially supporting structure ‘the syncytioskeletal layer’ is described. It is an apparently continuous and complex polymeric network covering the villous tree, a surface of the order of 10m 2 in area in the full term placenta (Aherne & Dunnill 1966). It is suggested that this layer plays a part in morphogenesis of the villous tree.