title: Chemically-induced temperature sensitive mutants of dengue virus type 2. I. Isolation and partial characterization.
abstract: Temperature sensitive (ts) mutants of dengue virus type 2 (DEN-2, TH-36 isolate) were induced by replication in primary hamster kidney cells treated with 5-azacytidine. Seven ts mutants were obtained from 138 clones isolated by an immunofluorescent cloning technique. Of these 7 ts mutants, 5 were sufficiently stable to permit partial characterization. Complementation was detected at very low but statistically significant levels between some ts mutants at 40 degrees C. Viral double-stranded RNA production was evaluated in LLC-MK2 cells at 30 degrees and 40 degrees C by micro-quantitative complement fixation. The results of complementation tests and RNA production tests indicated that the 4 of 5 stable ts mutants constitute 3 separate complementation groups (2 RNA+ and 1 RNA-groups), while a fifth ts mutant was RNA- but non-complementable. The data presented here indicate that a genetic system can be developed without employing traditional plaque or cytopathology methods. Further, the 5 DEN-2 ts mutants are believed to represent the only set of complementation-positive flavivirus mutants so far isolated.
mesh_terms: D001374:Azacitidine; D046508:Culture Techniques; D003716:Dengue Virus / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D005816:Genetic Complementation Test; D009153:Mutagens; D012367:RNA, Viral / Q000096:biosynthesis; D013696:Temperature; D014779:Virus Replication
chemical_list: D009153:Mutagens; D012367:RNA, Viral; D001374:Azacitidine