Recombinant influenza viruses made at 25 and 33” in Madin-Darby canine kidney (MDCK) cells using the cold-adapted A/Ann Arbor/6/60 virus and the wild-type A/ Alaska/6/‘77 virus were biologically and genetically analyzed. Eight recombinants were separated into two phenotypic groups based on cold-adapted (ca) and temperature-sensitive (ts) markers: ca and ts, ca and non-m. The ca recombinants sho...

BACKGROUND HIV-1 subtype B (HIV-1B) still dominates in resource-rich countries but increased migration contributes to changes in the global subtype distribution. Also, spread of non-B subtypes within such countries occurs. The trend of the subtype distribution from the beginning of the epidemic in the country has earlier not been reported in detail. Thus the primary objective of this study is t...

The level of synthesis and extracellular release of human immunodeficiency virus type 1 Gag by insect cells was analyzed, using eight different recombinants of Autographa californica nuclear polyhedrosis virus harboring various constructs of the gag gene, cloned under the polyhedrin promoter. The results obtained suggested that gag expression was mainly regulated at the transcriptional level an...

The leukemogenic mink cell focus-forming (MCF) retroviruses such as MCF 247 have biological properties distinct from those of their ecotropic progenitors. Nucleotide sequences encoding portions of gp70, Prp15E, and the long terminal repeat differ between the two types of viruses. To investigate the role of each of these genetic elements in determining the biological properties of MCF viruses, w...