Current work includes studies on plasma membrane biogenesis including the sites of synthesis and assembly of phospholipids and of enzymatic proteins. The approach utilizes combined biochemical, cytochemical and electron microscopic techniques and the major studies involve secreting cells of the ducklings' salt gland stressed by salt ingestion. Other systems evincing biogenesis of membranes include rapidly dividing cells, myelin formation and greening of chloroplasts. A related aspect involves enzymatic composition of plasma membrane and enzymes involved in phospholipid synthesis. The main emphasis concerns Na K ions ATPase (development of an immunocytochemical method and utilizing ouabain derivatives to localize the activity), phosphatidic acid phosphatase and CDP amine and other diglyceride transferases. Some of these methods are applied to studies involving type II pneumocytes and the biogenesis of pulmonary surfactant. BIBLIOGRAPHIC REFERENCES: Heckman, C.A., Friedman, J.S., Skehan, P.J. and R.J. Barrnett. Localization and Partial Characterization of Acyltransferases Present During Rapid Membrane Formation in the Drosophila Melanogaster Embryo. Developmental Biology, 55: 9-32, 1977. Feigenson, M.E. and R.J. Barrnett. Combined Pharmacological and Fine-Structural Studies of Choline O-Acetyltransferase at the Myoneural Junction. Brain Research, 119: 155-179, 1977.