Fig 1.
Developmental stages of Catharsius molossus.
Adult males prepare dung to construct brood balls, and the brood balls will be sealed with dry grass. The brood ball forms a unique three-layer structure: soil-dung-soil. The eggs are laid on the inner soil layer.
Table 1.
Sampling information.
Fig 2.
The alpha and beta diversities of the gut microbiome of adult C. molossus dung beetles on either side of the Tanaka-Kaiyong Line.
(a) Bacterial Faith’s Phylogenetic Diversity (Faith_pd) Index; (b) PCoA plot of dung beetle gut bacteria based on the Unweighted Unifrac distance matrix. Alpha and beta diversity of the gut microbial communities of adult C. molossus from different localities. (c) Bacterial Faith’s Phylogenetic Diversity (Faith_pd) Index. (d) Bacterial Shannon Index. (e) PCoA plot of dung beetle gut bacteria based on the Weighted Unifrac distance matrix. (f) Fungal Faith’s Phylogenetic Diversity (Faith_pd) Index. (g) Fungal Shannon Diversity Index. (h) PCoA plot of dung beetle gut fungi based on the Weighted Unifrac distance matrix. Note: * indicates p < 0.05, ** indicates p < 0.01, *** indicates p < 0.001.
Fig 3.
Composition of the gut microbial communities of adult C. molossus from different localities.
(a) Stacked bar chart of the top 25 abundant gut bacteria at the genus level; (b) Stacked bar chart of the top 25 abundant gut fungi at the genus level.
Fig 4.
Significant differences in the gut microbial communities of adult C. molossus from different localities revealed by LEfSe (Linear Discriminant Analysis Effect Size) analysis.
(a) Differential gut bacteria present in dung beetles from different localities (LDA score > 3, P < 0.05); (b) Differential gut fungi present in dung beetles from different localities (LDA score > 3, P < 0.05).
Fig 5.
Alpha diversity of the gut microbial communities of C. molossus at different developmental stages and in their brood balls.
(a) Bacterial Faith’s Phylogenetic Diversity (Faith_pd) Index; (b) Bacterial Shannon Index; (c) Fungal Faith’s Phylogenetic Diversity (Faith_pd) Index; (d) Fungal Shannon Diversity Index. Groups that do not share the same letter indicate significant differences between them (p < 0.05), whereas those with the same letter show no significant difference. And* indicates p < 0.05, ** indicates p < 0.01, *** indicates p < 0.001.
Fig 6.
Analysis of β-diversity in the gut microbial communities of C. molossus at different developmental stages and their brood balls.
PERMANOVA (Permutational Multivariate Analysis of Variance) is used to detect differences between different groups. (a) PCoA plot based on the Unweighted Unifrac distance matrix, where each symbol represents the bacterial community of a sample, and colors indicate different groups; (b) PERMANOVA test for bacterial community diversity across different groups based on the Unweighted Unifrac distance matrix, pseudo-F = 2.154, p-value = 0.001; (c) PCoA plot based on the Weighted Unifrac distance matrix, where each symbol represents the bacterial community of a sample, and colors indicate different groups; (d) PERMANOVA test for bacterial community diversity across different groups based on the Weighted Unifrac distance matrix, pseudo-F = 2.685, p-value = 0.001; (e) PCoA plot based on the Weighted Unifrac distance matrix, where each symbol represents the fungal community of a sample, and colors indicate different groups; (f) PCoA plot based on the Unweighted Unifrac distance matrix, where each symbol represents the fungal community of a sample, and colors indicate different groups; (g) PERMANOVA test for bacterial community diversity across different groups based on the Weighted Unifrac distance matrix, pseudo-F = 2.5708, p-value = 0.001; (h) PERMANOVA test for bacterial community diversity across different groups based on the Unweighted Unifrac distance matrix, pseudo-F = 1.8631, p-value = 0.001.
Fig 7.
Composition of microbial communities in C. molossus at different developmental stages and their brood balls.
(a) Stacked bar chart showing the bacterial community composition at the phylum level for different samples; (b) Stacked bar chart showing the top 25 abundant bacterial genera in different samples; (c) Stacked bar chart showing the fungal community composition at the phylum level for different samples; (d) Stacked bar chart showing the top 25 abundant fungal genera in different samples.
Fig 8.
Gut bacteria with significant differences across different groups (LDA score > 3, P < 0.05) revealed through LEfSe analysis.
Table 2.
Core gut bacterial genera of adult C. molossus from different localities.
Table 3.
Core gut bacterial genera of C. molossus at different developmental stages.
Fig 9.
Comparison of predicted KEGG Ortholog groups (KOs) count at pathway level 2.
(a) Through LEfSe (Linear Discriminant Analysis Effect Size) analysis, significant differences in Pathway L2 metabolic pathways were identified in the gut microbiome of C. molossus from different localities (LDA score > 3, P < 0.05); (b) Reveals significant differences in Pathway L2 metabolic pathways between the gut microbiome of adult and larval C. molossus. Histograms based on PICRUSt2 predictions show the average proportion of each metabolic pathway at Pathway L2 in different groups, with differences between groups indicated by 95% confidence intervals; (c) Highlights significant differences in Pathway L2 metabolic pathways between the gut microbiome of younger and older larvae of C. molossus. Histograms based on PICRUSt2 predictions display the average proportion of each metabolic pathway at Pathway L2 in different groups, with intergroup differences indicated by 95% confidence intervals.