Fig 1.

Construction and characterization of recombinant CDVs. (A) Schematic representation of pCDV^SH full-length infectious clone. A subclone containing the H-L gene boundary was produced following digestion of pCDV^SH with RsrII and SwaI to facilitate the introduction of a unique PmeI site (B) as indicated by the gray shading. (C) An additional transcription unit containing EGFP or dTom was inserted at the H-L gene boundary using the unique PmeI site to produce the pCDV^SHEGFP(6) and pCDV^SHdTom(6) full-length clones. (D) Multistep growth curves of CDV^R252, CDV^5804P, CDV^SH, rCDV^SHdTom(6), and rCDV^SHEGFP(6) in VerodogSLAM cells. Virus was harvested at 12-h intervals up to 96 h postinfection. Viral titers were determined as the number of TCID₅₀/ml in an endpoint titration test. Measurements shown are averages of triplicates ± SE. (E) Phase-contrast photomicrographs taken at 72 h.p.i. of VerodogSLAM cells with Opti-MEM (mock), CDV^R252, CDV^5804P, CDV^SH, rCDV^SHdTom(6), and rCDV^SHEGFP(6). Bar, 200 μm.