Communities Diversity Of The Gut Microbiota In Odontolabis Fallaciosa

Gut microbes play an important role in the nutrient supply,digestion and absorption,growth and development and immune defense of insects,and help to broaden their ecological niche.Lucanidae has become a unique branch of the order Coleoptera because of its significant Sexual dimorphyism,Male trimorphism and sex selection behavior.It is also a hot group of attention in the Insecta.Most adults of the family Lucanidae are fed with fruit juice or rotten fruit,and larvae get nourishment by decomposing dead wood or humus.Therefore,it occupies a unique niche in the carbon cycle of forest ecosystems,and is also of great value in the decomposition and utilization of biomass energy.However,there are few studies on the intestinal microbes of this kind of insects based on high-throughput sequencing.Odontolabis fallaciosa is a typical representative of the Lucanidae.For the first time,the 16S rDNA V3-V4 region of the midgut microbial community in the O.fallaciosa was studied by high throughput sequencing.The difference of gut microbes among different sex and mandibles types was studied.The composition and differences of intestinal microbes were analyzed,and their roles in the energy demand of the O.fallaciosa were discussed.In order to further explore the function of intestinal microorganism and provide a theoretical reference for its role in phenotype evolution.The main points of this dissertation are listed as follows:1?A total of 3255 OTUs were obtained by sequencing,and 42 phyla,118 classes,361 families and 585 genera were annotated;Proteobacteria,Bacteroidetes,Firmicutes,Tenericutes,Fusobacteria,Euryarchaeota,Nitrospirae is the highest level in the gut microbial community of O.fallaciosa.The dominant genera of more than 1%are dominant phyla,including Proteobacteria,Bacteroidetes and Firmicutes.There are Acinetobacter,Dysgonomonas,Bartonella,Chryseobacterium,Enterococcus,Porphyromonas,Caloramator,Ochrobactrum,Morganella,Serratia,Telmatospirillum,Flavobacterium,Klebsiella,Comamonas,and Desulfovibrio.2?The differences in the relative abundance of the bacterial communities in different sex(Sexual dimorphyism)groups were different:Large male have the largest number of dominant phylum,followed by female,medium-sized male and small male.In the dominant phylum,the abundances of Firmicutes are higher in the large male and female.The Firmicutes have an important effect on the nutrition and absorption of food,and may have a beneficial effect on the nutritional utilization of the large male and female.At the level of the genus,the number of dominant genera is the female,followed by large male,medium-sized male and small male.3?The differences in the relative abundance of the bacterial communities in different male mandibles types(Male trimorphism)groups were different:Large male have the largest number of dominant phylum than large male and small male.At the level of the genus,the number of dominant genera is large male,followed by medium-sized male and small male.4?Analysis of the complexity of microbial bacterial communities about the observed species and shannon in alpha diversity index found that female.had significant difference with large male,medium-sized male and small male.In beta diversity,the PCA analysis shows that the distance between the female samples is closer,indicating that the community composition is more stable.Female had significant difference with large male,medium-sized male and small male by analysis of similarities,large male and medium-sized male are the same.5?The results of metabolic function prediction with PICRUST showed that the potential functional gene composition was similar.But the abundance of functional genes that affect food degradation and nutrient absorption in female and large male is the highest.These results suggest that the communities diversity of microbiota in the gut of O.fallaciosa adults:The composition and abundance of gut microbial communities in females are significantly different from those in males;female had significant difference with large male,large male and medium-sized male are the same.This difference may be related to the nutritional needs of males and mandibles types.It also provides a theoretical reference for further exploring the function of the intestinal microorganism and its possible role in the evolution of the disease.