Gut microbial compositions mirror caste-specific diets in a major lineage of social insects.

Saria Otani,Aram Mikaelyan,Michael Poulsen,Panagiotis Sapountzis,Mariya Zhukova,N'Golo Abdoulaye Koné,Rafael Rodrigues Da Costa

doi:10.1111/1758-2229.12728

Abstract

SummarySocial insects owe their ecological success to the division of labour between castes, but associations between microbial community compositions and castes with different tasks and diets have not been extensively explored. Fungus‐growing termites associate with fungi to degrade plant material, complemented by diverse gut microbial communities. Here, we explore whether division of labour and accompanying dietary differences between fungus‐growing termite castes are linked to gut bacterial community structure. Using amplicon sequencing, we characterize community compositions in sterile (worker and soldier) and reproductive (queen and king) termites and combine this with gut enzyme activities and microscopy to hypothesise sterile caste‐specific microbiota roles. Gut bacterial communities are structured primarily according to termite caste and genus and, in contrast to the observed rich and diverse sterile caste microbiotas, royal pair guts are dominated by few bacterial taxa, potentially reflecting their specialized uniform diet and unique lifestyle.

Highlights

Gut bacterial communities are structured primarily according to termite caste and genus and, in contrast to the observed rich and diverse sterile caste microbiotas, royal pair guts are dominated by few bacterial taxa, potentially reflecting their specialized uniform diet and unique lifestyle
Compositional and functional differences across sterile caste gut communities The vast majority of bacterial taxa were evenly distributed across minor workers, major workers and soldiers in M. natalensis and the two Odontotermes species (Fig. 1A)
Arcobacter and Enterobacter 4 were the only two OTUs that were common in workers of both termite genera (Fig. 1B), consistent with the DESeq2 results that the vast majority of the differentially abundant OTUs were distinct between M. natalensis and Odontotermes spp. (Fig. 1B and Supporting Information Table S12)

Summary

Social insects owe their ecological success to the division of labour between castes, but associations between microbial community compositions and castes with different tasks and diets have not been extensively explored. Fungus-growing termites associate with fungi to degrade plant material, complemented by diverse gut microbial communities. We explore whether division of labour and accompanying dietary differences between fungus-growing termite castes are linked to gut bacterial community structure. We characterize community compositions in sterile (worker and soldier) and reproductive (queen and king) termites and combine this with gut enzyme activities and microscopy to hypothesise sterile caste-specific microbiota roles. Gut bacterial communities are structured primarily according to termite caste and genus and, in contrast to the observed rich and diverse sterile caste microbiotas, royal pair guts are dominated by few bacterial taxa, potentially reflecting their specialized uniform diet and unique lifestyle

Introduction

Results and discussion

Conclusions