Composition and function of the microbiotas in the different parts of the midgut of Pyrrhocoris sibiricus (Hemiptera: Pyrrhocoridae) revealed using high-throughput sequencing of 16S rRNA

Abstract

In pyrrhocorids, digestion of food occurs mainly in the midgut, which is divided into four parts (M1-M4), and takes between three and four days. Food is retained in M1 for about 5 h and passes quickly through M4. However, food is retained in M2 and M3 much longer, about 70 to 90 h. The different stages in digestion may be influenced by different microbial populations in the different parts of the midgut. In the present study, the microbiota in the four parts of the midgut of Pyrrhocoris sibiricus were analysed in detail using high-throughput sequencing of the 16S rRNA V3-V4 region. The most abundant bacteria in M3 were Actinobacteria (Coriobacteriaceae) whereas it was Proteobacteria (gammaproteobacteria) in M1, M2 and M4. Actinobacteria was the second most abundant bacterial group in M2. According to the PCA analysis, M2 and M3 have the most similar bacterial communities. Burkholderia, which is closely related to the plant-associated beneficial and environmental (PBE) group, was also found in M1, M2 and M4. Predictive functional profiles of the metagenomes revealed that metabolism mostly occurred in M2 and M3. The PICRUSt results were consistent with the 16S rRNA metagenomic analysis and indicate that the bacteria in M2 and M3 play an important role in degrading complex dietary components.

Keywords

• pyrrhocoridae
• pyrrhocoris sibiricus
• digestion
• gut microbiota
• community structure
• functional profiling
• next-generation sequencing
• 16s rrna gene