Synthesis by Lymphoid Cells Transformed in Vitro by Abelson Murine Leukemia Virus

Edward J. Siden and David Baltimore Department of Biology and Center for Cancer Research Massachusetts Institute of Technology Cambridge, Massachusetts 02139 Daniel Clark and Naomi E. Rosenberg Department of Pathology and Cancer Research Center Tufts University School of Medicine Boston, Massachusetts 02111 Summary The majority of cell lines derived by infection of murine bone marrow cells with Abelson murine leukemia virus (A-MuLV) synthesize a p chain but no detectable light chain. Aside from this p-only phenotype, lines that make only light chain, both chains or no immunoglobulin-related polypep- tides have also been found. Two lines have been studied in detail: one that makes only p chain and one that makes only