Expression of H-2 and Moloney leukemia virus-determined cell-surface antigens in synchronized cultures of a mouse cell line.

A mouse cell line derived from bone marrow (JLS-V9) was infected in vitro with Moloney leukemia virus. After the cell-surface antigens specified by this virus appeared, cells were synchronized in mitosis by a short treatment with colcemid. The expression of H-2- and virus-determined surface antigens was monitored during one cell cycle by an indirect membrane-immunofluorescence test. The highest proportion of antigen-positive cells was found during the G1 period; the proportion dropped as the cells entered the S period, and remained low until they entered the G1 period of the next cycle. The H-2- and virus-determined surface antigens were temporally coexpressed.