Selection of L Cell Sublines Resistant to (E)-5-(2-Bromovinyl)-2′-Deoxyuridine

A mouse thymidine kinase (TK) deficient L cell subline and L cell sublines biochemically transformed by herpes simplex virus TK were cultured in the presence of increasing concentrations of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) which inhibited the growth of all sublines, and resistant sublines were isolated. Their growth properties were dependent on the medium condition used for selection. One subline had lost viral TK activity, while another retained viral TK activity with altered sensitivity of TK to BVDU in comparison with that of the original subline. Growth characteristics and TK activity of sublines are discussed.