Number of CFUs in sexually active and virgin males. Virgin males (□) had significantly higher bacterial loads than sexually active males (■) 24 hours post infection (p = 0.02). However, the bacterial loads of virgin and mated males were not significantly different 0 hours after infection. Compared to the bacterial load at 0th hour post infection, the bacterial load of both virgin and mated males was higher at 24 hours post infection (p = 0.03), indicating that the bacteria grew within both virgin and infected males. Bacterial loads were determined by homogenizing flies in groups of three and plating them on LB agar plates which were then incubated at 27°C for 24 hours. The number of CFUs in each plate was then counted as a measure of bacterial load. The experiment had four independent blocks with 8–10 replicates within each block × treatment combination. The values plotted are Mean (± S.E.) averaged across the four block means. Data was analyzed using a three factor mixed model ANOVA where time and mating status were modeled as fixed factors crossed amongst themselves and with random blocks. The results are summarized in Table 3. Sham infected controls did not yield any colonies at 0 and 24 hours post infection (data not shown).
Gupta et al. BMC Evolutionary Biology 2013 13:185 doi:10.1186/1471-2148-13-185