Figure 6

Quantitative measurements of the effect of the mode of inoculation on the sensitivity of carp to CyHV-3 infection during the early stages of development. The timeline of this experiment has been described in Figure 5. Fish were mock-inoculated or inoculated with the FL LUC strain using three modes of infection: immersion in infectious water (B), immersion in infectious water just after removing the epidermal mucus (M), and by IP injection of the virus (IP). Fish were analyzed by IVIS at 24 hpi. (a) The average radiance (p/sec/cm²/sr) emitted by individual infected fish (n?=?30 per group) corrected for the background of each image is presented by dots. For each group of inoculated fish (according to time of inoculation and mode of inoculation), the mean?+?SD is presented as grey bars. For each time point, a group of mock-inoculated fish was analyzed to define the threshold of positivity (green bars), defined as the mean?+?3 SD (p?<?0.00135). Red dots represent inoculated fish defined as positive based on their average radiance being higher than the threshold or based on the expression of a spot of light (even if their average radiance was below the threshold). The data obtained for the different modes of inoculation for a considered time of inoculation were compared by two-way ANOVA. (b) The number of positive fish among 30 analyzed infected fish. The data obtained for the different modes of inoculation for each time of inoculation were compared using the chi-squared test. *p?<?0.05, **p?<?0.01, *** p?<?0.001, and ****p?<?0.0001.