| Gut microbiome plays an important role in nutrient absorption,substance metabolism and immune regulation of animal hosts.However,due to its parasitism in the host intestinal microenvironment,the persistence and diversity of gut microbiome are also affected by host factors,such as host diet and phylogeny,which are widely considered to be the main factors shaping the diversity of intestinal bacterial community.Ants are one of the most abundant and dominant species in the world.They are also representative of the biology and ecology of social insects and are essential for the maintenance and functioning of terrestrial ecosystems.But some members of Solenopsis invicta,may also act as invasive species,damaging local biodiversity.At present,our understanding of ant gut bacteria is limited to a few ant members,and there is no unified conclusion on the factors shaping the composition,structure and diversity of ant gut bacteria on a wider scale.Therefore,on the basis of using meta barcoding technology to determine the feeding habits of ants in different subfamilies,we collected 47 ant species(including 52 ant colonies,29 genera,8 subfamilies)as research objects,and determined the gut bacteria of these ant species by 16 S r RNA high-throughput sequencing technology.Based on the original bacterial OTU data,the dominant bacterial composition of all samples at the level of phyla and family was determined.Based on the grouping strategy,specific phyla and orders of bacteria were identified.The Alpha diversity and Beta diversity of each diet group and phylogenetic group were calculated at the overall bacterial level,75% core bacterial level and 50% core bacterial level,and the intensity of the influence of diet and phylogenetic groups was compared.Finally,the differences of intestinal bacterial communities in different geographical populations were compared.The main findings include:(1)Composition of ant intestinal bacteria.At the level of bacterial phyla,there were three core groups of bacterial phyla,namely Proteobacteria,Actinobacteria and Firmicutes.At the bacterial level,Moraxellaceae,Anaplasmataceae(94/126),Nocardiaceae(118/126)and Morganellaceae(102/126)were the core microbiota families.Other more bacterial families were present in each sample at lower abundance and lower infection rates.(2)Dominant bacteria and specific bacteria between groups.Among the top 50 bacterial phyla in abundance,the four major bacterial groups were Proteobacteria,Bacteroidetes,actinobacteria and Firmicutes,both in diet group and subfamily group.Erysipelotrichales and Enterobacterales were endemic in the gut of carnivorous ants,and Corynebacteriales was specific bacteria in phytophagous ants.Among the different ant subfamilies,Erysipelotrichales and Entomoplasmatales were found to be specific bacteria in the subfamily Emilionidae,while Pseudomonadales and Entomoplasmatales were found to be the main endemic bacteria in the subfamily Emilionidae,and the abundance of these endemic bacteria was relatively low.Enterobacteriaceae are endemic bacteria of ants in the Formicinae family.(3)The driving effect and intensity of diet and phylogeny on ant gut bacteria.In terms of Alpha diversity,at the bacterial OTU level and at the phylum level,the gut bacteria of ants in different diet groups showed significant statistical differences,and there were also significant differences among different subfamily groups,which indicated that the diversity of ant gut bacteria was affected by diet and phylogeny.In terms of Beta diversity,at the bacterial OTU level and at the phylum level,there were significant statistical differences among almost different dietary groups and phylogenetic groups.However,the significant differences of dominant bacteria between groups indicated the influence of diet habits and phylogeny on the composition of intestinal bacteria in ants.The result of CCA showed that phylogeny had a greater effect on the composition of ant gut bacteria than diet.(4)Differences in gut bacteria among different geographical populations.Although the synergistic effect of geographical differences and seasonal variations caused obvious differences in bacterial abundance for some species,it had little effect on overall bacterial diversity.In our result,individual case studies showed that location had a significant effect on some ants that did not have a stable bacterial community in their gut,but had little effect on those whose gut bacteria were stable and formed long-term symbiotic relationships with symbionts.In conclusion,ant gut bacteria are abundant and diverse,but their composition,structure and diversity are influenced by both diet and phylogeny.Based on the knowledge of ant gut bacteria,it provides a new perspective for us to further understand the ecological adaptation of ants,and provides useful data reference for the biological control of related species. |
