Additional file 1 of Serotonin modulates insect gut bacterial community homeostasis
Creators: name: Zeng, Tian
name: Su, Hong-ai
name: Liu, Ya-lan
name: Li, Jian-fang
name: Jiang, Ding-xin
name: Lu, Yong-yue
name: Qi, Yi-xiang
Publisher: name: figshare
Year: 2022
Subjects: subject: Microbiology
subject: FOS: Biological sciences

description: Additional file 1: Fig. S1. Schematic of 5-HT synthesis. Serotonin (5-HT) is synthesized in a two-step process. The amino acid tryptophan is first hydroxylated by Tryptophan hydroxylase (TPH). This is the rate-limiting step in 5-HT synthesis. In insects, two gene products, TRH and TPH, are capable of converting tryptophan into 5-hydroxytryptophan (5-HTP). In the second step, 5-HTP is decarboxylated to serotonin by Dopa decarboxylase (DDC). Fig. S2. Effect of 5-HTP treatment on midgut and hindgut bacterial composition in B. dorsalis at genus level. Fig. S3. Effect of 5-HTP treatment on the relative abundance of S. marcescens and P. alcalifaciens in the gut of B. dorsalis. (a) Phylogenetic analysis of the identified S. marcescens and P. alcalifaciens operational taxonomic units (OTUs) with 18 related bacteria. The evolutionary history was inferred by using the neighbor-joining method conducted in MEGA 6 software. A sequence of Pseudomonas entomophila was used as the outgroup. Bootstrap values (percentages of 1,000 tree replications) greater than 50% are displayed at the nodes. Sequence GenBank accession numbers are shown in parentheses. (b, c) 5-HTP treatment increased the relative abundance of (b) S. marcescens and (c) P. alcalifaciens in the gut of B. dorsalis. Fig. S4. BdTPH regulates gut bacterial composition in B. dorsalis. (a) Histogram showing changes at the genus level. (b) Relative abundance of bacteria at the genus level in B. dorsalis gut postinjection of dsBdTPH and dsGFP by 16S rDNA sequencing. To restore the 5-HT level, BdTPH-silenced flies were treated with 1-mM 5-HTP by feeding after dsRNA injection. Fig. S5. BdTRH knockdown does not affect the gut commensal microbiome of B. dorsalis. (a) Gut BdTRH silencing efficiency in B. dorsalis at 72 h postinjection with 1.5 μg of dsGFP or dsBdTRH. (b) Effect of BdTRH silencing on gut total bacterial load. (c) Effect of BdTRH knockdown on gut S. marcescens burden. The housekeeping β-actin gene was used as an endogenous control. Fig. S6. Gut BdTPH silencing efficiency in axenic B. dorsalis. (a-b) The efficacy of elimination of gut bacteria confirmed by culturing B. dorsalis gut homogenates on LB agar plates (a) and by performing PCR analysis (b) on gut homogenates using universal 16S rRNA gene primers. (c) The mRNA level of BdTPH in axenic B. dorsalis gut at 96 h postinjection with 2.0 μg of dsGFP or dsBdTPH. Data were normalized to expression levels in dsGFP-treated flies. Fig. S7. Effect of BdTRH silencing on gut BdDuox expression level in B. dorsalis. Fig. S8. Expression of six genes related to IMD pathway in the guts of BdTPH-silencing B. dorsalis. The GFP dsRNA-treated flies served as controls. Gene expression of each sample was normalized to that of controls (taken as 1). Fig. S9. Relative expression levels of BdTPH after the bacteria Klebsiella sp. were introduced into the guts of antibiotic-treated flies. Fig. S10. The effect of 1mM 5-HTP on liquid food consumption by B. dorsalis.