PGRPLC controls gut bacteria modulating Plasmodium infections.

(A) Relative numbers of bacteria in dsGFP-treated control or PGRPLC kd A. gambiae females, fed on sugar or P. berghei-infected mice 24 h before sampling. Quantification was performed by quantitative genomic PCR of a conserved bacterial 16S rDNA fragment and referenced to sugar-fed controls. Error bars indicate standard errors. Comparisons between all the samples were performed using the Student's t-test and the results are shown as letters above each bar. Same letters indicate no significant difference, while different letters indicate at least P<0.05. In this graph all P values were <0.001. (B) CEC1 relative expression in dsGFP-treated control and PGRPLC kd A. gambiae females fed on sugar, naïve blood or P. berghei-infected blood. Expression in sugar-fed controls is used as a reference. As in (A) different letters above each bar indicate Student's t-test P value<0.001. (C) Median numbers and distribution of P. berghei oocyst intensities in Gentamycin-treated (+) and untreated (−) mosquitoes. Boxes include 50% of the data and whiskers indicate the range in a log₁₀-transformed scale. Median is shown with the bar and number within each box. ***, P<0.001 of Mann Whitney test. (D) Median numbers and distribution of P. berghei oocyst intensities in Gentamycin-treated (+) and untreated (−) PGRPLC kd and dsGFP-treated controls shown in a log₁₀-transformed scale. As above, different letters above each dataset indicate statistically significant differences: P<0.001 for dsGFP(−)/dsGFP(+) and P<0.01 for dsGFP(−)/LCkd(−) and dsGFP(−)/LCkd(+). (E) Prevalence of melanized ookinetes in the mosquitoes presented in (D). Statistical analysis was performed with the Fisher's exact test: dsGFP(−)/LCkd(−), P<0.05; dsGFP(+)/LCkd(−), P<0.0001; LCkd(−)/LCkd(+), P<0.001. (F) Median numbers and distribution of P. berghei oocyst intensities in Enterobacter-infected (+) and non-infected (−) mosquitoes. Note that the y-axis is log₁₀-transformed. (G) Median numbers and distribution of P. berghei oocyst intensities in Enterobacter-infected (+) and non-infected (−) dsGFP-treated mosquitoes, and in Enterobacter-infected PGRPLC kd and REL2 kd mosquitoes. Different letters above each dataset indicate statistically significant differences as follows: P<0.005 for dsGFP(−)/dsGFP(+) and P<0.001 for dsGFP(+)/LCkd(+) and dsGFP(−)/LCkd(+). (H) Prevalence of melanized ookinetes in the mosquitoes presented in (G). dsGFP(−)/LCkd(+), P<0.05; dsGFP(−)/REL2kd(−), P<0.0001; dsGFP(+)/LCkd(+), P<0.0001; dsGFP(+)/REL2kd(+), P<0.05; LCkd(+)/REL2kd(+), P<0.005.