FIG. 2.
Generation of UL13 mutant MDVs and evaluation of their ability to induce MD and horizontally transmit to contact chickens. (A) Schematic diagram showing the UL13 ORF flanked by overlapping UL14 and UL12 ORFs and reversed in the figure for simplicity. Also shown are the 11 (I to XI) kinase domains contained within the conserved UL13 protein. Two UL13 mutants were generated from the transmission-competent BAC clone (parental) as described in the text. (B) RFLP analysis of DNA obtained from parental virus (lane 1) and UL13K270M (lane 2), UL13K170M (lane 3), and UL13M170K (lane 4) BAC clones using BamHI restriction patterns. No extraneous alterations are evident in all clones. The molecular size marker (MW) used is the 1-kb Plus DNA ladder (Invitrogen). (C) Same as in Fig. 1C. No significant differences in plaque sizes were seen between each virus using Student's t tests. (D) Same as in Fig. 1D. All contact chickens housed with the UL13K170M (kinase mutant) were negative for MD lesions following necropsy and negative for MDV genomic copies in the blood using qPCR assays.