%0 Journal Article %A Heitman, Catherine Krebs %A Innes, Cynthia L. %A Jetten, Anton M. %A Boone, Lawrence R. %T Analysis of Fv-1 restriction in two murine embryonal carcinoma cell lines and a series of differentiated derivatives %D 1991 %J Journal of General Virology, %V 72 %N 3 %P 609-616 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-72-3-609 %I Microbiology Society, %X We have used antibiotic-resistant retrovirus vectors rescued by Fv-1-sensitive murine leukaemia viruses (MuLV) to examine the Fv-1 phenotype of two undifferentiated embryonal carcinoma (EC) cell lines derived from teratocarcinomas of mouse strain 129. In addition, a set of EC cell-derived differentiated cell lines was analysed. Restriction of both B-tropic and endogenous N-tropic virus is characteristic of the Nr-type restriction reported in mouse strain 129. However, results indicate that Fv-1 restriction is not expressed in the PCC4.aza1R EC cell line. In contrast, the F9 EC cell line showed a strong restriction of the B-tropic pseudotyped vector but failed to restrict endogenous N-tropic pseudotypes. The Fv-1 gene thus seems to be differentially expressed in two EC cell lines derived from the same mouse strain. Furthermore, the selective restriction of B-tropic but not endogenous N-tropic MuLV in F9 cells suggests that these activities function independently of each other. Analysis of PCC4.aza1R-derived differentiated cell lines revealed that three fibroblast cell lines derived by retinoic acid-induced differentiation were also phenotypically silent for Fv-1. However, a pre-adipocyte line established following simultaneous exposure to retinoic acid and 5-azacytidine showed strong restriction of both B-tropic and endogenous N-tropic MuLV. Although additional data suggest that there is no correlation between the differentiated pre-adipocyte phenotype and Fv-1 expression, our results nonetheless show that Nr restriction can be observed in some derivatives of PCC4.aza1R cells, presumably by activating expression of the Fv-1 gene. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-72-3-609