The University of Pennsylvania Human Genetics Center has a Clinical Genetics program and a Cell Center program. The former is actively engaged in the search for animal models of human genetic diseases by the screening of abnormal cats and dogs for biochemical and cytogenetic abnormalities. The project in the area of sociologic and legal problems in human genetics is concerned with the design of evaluation programs in the delivery of human genetic care. Projects in the Cell Center are concerned with hormonal interactions using human lymphoblastoid cells; transduction of genetically deficient human cells with bacterial genes; serine and glycine biosynthesis in cultured human cells; studies of chrondrogenesis and myogenesis in primary cell cultures; the genetics of ribosomes; the study of human metabolic disorders in cell culture; the control of expression of differentiation in cell culture and the use of cell hybrids to study differentiation; and the study of membrane antigens in lymphoblastoid lines.