PMID- 14645562 OWN - NLM STAT- MEDLINE DCOM- 20040113 LR - 20191210 IS - 0022-538X (Print) IS - 1098-5514 (Electronic) IS - 0022-538X (Linking) VI - 77 IP - 24 DP - 2003 Dec TI - High-frequency homologous recombination between baculoviruses involves DNA replication. PG - 13053-61 AB - We determined the frequency of DNA recombination between Bombyx mori nucleopolyhedroviruses (BmNPVs) and between BmNPV and the closely related Autographa californica NPV (AcMNPV) in BmN cells, Sf-21 cells, and larvae of Heliothis virescens. The BmN cells were coinfected with two BmNPVs, one with a mutation at the polyhedrin gene (polh) locus and a second carrying a lacZ gene marker cassette. Eleven different BmNPV mutants carrying the lacZ gene marker at various distances (1.4 to 61.7 kb) from polh were used for the coinfections. The Sf-21 cells and larvae of H. virescens were coinfected with wild-type AcMNPV and 1 of the 11 lacZ-marked BmNPV mutants. In BmN cells, high-frequency recombination was detected as early as 15 h postcoinfection but not at 12 h postcoinfection. At 18 h postcoinfection, the mean frequency of recombination ranged between 20.0 and 35.4% when the polh and lacZ marker genes were separated by at least 9.7 kb. When these marker genes were separated by only 1.4 kb, the mean frequency of recombination was 2.7%. In BmN cells, the mean recombination frequency between two BmNPVs increased only marginally when the multiplicity of infection of each virus was increased 10-fold. In Sf-21 cells and the larvae of H. virescens, the recombination frequency between BmNPV and AcMNPV was