Fig. 2

BdTPH contributes to the maintenance of gut microbiota in B. dorsalis. a Expression of TPH and TRH in the B. dorsalis gut. RpL32 was used as an internal reference gene. b Relative expression levels of BdTPH and BdTRH in the midgut and hindgut of B. dorsalis (n = 3). c Gut BdTPH silencing efficiency in B. dorsalis at 96 h postinjection with 2.0 μg of dsGFP or dsBdTPH. Data were normalized to expression levels in dsGFP-treated flies. d Effect of BdTPH knockdown on gut 5-HT level by HPLC detection post dsRNA injection. e–g Effect of BdTPH silencing on gut total bacterial load by e 16S rRNA quantification using real-time PCR and f, g colony-forming unit assay. h Relative abundance of the genera Serratia and Providencia postinjection of dsBdTPH and dsGFP by 16S rDNA sequencing. i BdTPH knockdown decreased the load of S. marcescens and j P. alcalifaciens in the gut of B. dorsalis. To restore the 5-HT level, BdTPH-silenced flies were treated with 1-mM 5-HTP by feeding after dsRNA injection. Data were analyzed using two-tailed unpaired t-test. Error bars indicate ± s.e.m.; *p < 0.05, **p < 0.01, ***p < 0.001. All results represent at least two independent experiments