Fig. 7

(a) Survival curves of 1-day ducklings after inoculation of 0.25 ml of the parental virus (10^4.0 TCID₅₀) or the rescued virus (10^4.0 TCID₅₀). All ten ducklings in control group live in healthy condition. (b) Genetic marker detection of the parental/rescued virus group. Total RNA was extracted from liver tissue of dead ducklings of the rescued virus group and the parental virus group, and then immediately used for transcription using the primers BamH I-detect-F/R. The amplified fragments were then digested with restriction enzyme BamH I and verified by electrophoresis in 2% agarose gel. (M) DNA Marker DL2000; (1) Fragments were amplified with the template RNAs of the parental virus group and then digested with BamH I; (2) Fragments were amplified with the template RNAs of the rescued virus group and then digested with BamH I. Nucleotide sequence alignment (c) and amino acid sequence alignment (d) were also conducted by the Clustal W method (DNA Star LaserGene software, DNAStar Inc. Madison, WI) to investigate genetic marker in both groups