FIG. 1.

Cloning strategy and structure of the CDV full-length cDNA plasmids. (Top) Schematic representation of the six fragments used to assemble the intermediate segment (11,950 nt) of pCDV. (Center) Intermediate vector. The T7 promoter (grey arrow), the CDV sequence from nt 1 to 2986 and from nt 14891 to 15690, and the hepatitis δ ribozyme and the T7 terminator (grey boxes) are shown. (Bottom) The two full-length plasmids pCDV3 and pCDVII. Two restriction sites (PacI [nt 7046 to 7053] and ApaI [nt 8927 to 8932]) were introduced into the 3′ and 5′ UTRs of the H gene of pCDV3 by site-directed mutagenesis to generate pCDVII. The first and last nucleotide of each fragment (referring to the complete genome) are indicated. The drawing is not to scale. The pBR322 vector backbone (thick line), fragments of the CDV genome (boxes), untranslated intergenic regions (three vertical lines), and the approximate locations of restriction sites used (arrows) are indicated.