Results from pairwise comparisons of OTU variance between honey bee castes (PERMANOVA based on Bray-Curtis dissimilarity matrix of read counts).

<p>P-values are Monte-Carlo estimates from 9,999 unrestricted permutations of the raw data.</p><p>Results from pairwise comparisons of OTU variance between honey bee castes (PERMANOVA based on Bray-Curtis dissimilarity matrix of read counts).</p

Family-level taxonomic composition of individual hindgut microbiomes in honey bees.

<p>Proportion of each taxa in total microbiome is represented by proportion of colored bar. Each bar represents one individual. Labels are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123911#pone.0123911.g001" target="_blank">Fig 1</a>.</p

Individual microbiomes cluster by host caste in honey bees.

<p>Red diamonds represent queens; green triangles males; purple triangles worker foragers; light blue squares worker nurses. (A) Dendrogram from average-linkage clustering of OTU frequency. Leaf labels follow the format caste:colonyID:individualID. Q—queens from mature colonies, Q7—7d old queens, M—males, F—foragers, N—nurses; colony ‘i1or2’—indoor colony; PL—pooled sample from indoor colony. (B) Non-metric multi-dimensional scaling plot of OTU frequency after log-transformation, which reduces the influence of the most abundant OTUs. Stress value: 0.13 (C) Summary of Shannon’s diversity index based on OTU frequencies within social castes. Lines represent the median index value, boxes demarcate the interquartile range, whiskers are the adjacent values, and markers are the outer adjacent values. Statistical comparison was made with ANOVA; letters represent significant pairwise differences with p<0.05 in post-tests. (D) Canonical analysis of principal coordinates based on a Bray-Curtis dissimilarity matrix of OTU frequencies (non-transformed). Individual bees are plotted on canonical axes (CAP) 1 and 2, which are calculated to maximize delimitation among castes.</p

Results from pairwise comparisons of OTU variance between honey bee castes with reduced influence of the most abundant OTUs (PERMANOVA based on Bray-Curtis dissimilarity matrix of log-transformed read counts).

<p>P-values are Monte-Carlo estimates from 9,999 unrestricted permutations of the raw data.</p><p>Results from pairwise comparisons of OTU variance between honey bee castes with reduced influence of the most abundant OTUs (PERMANOVA based on Bray-Curtis dissimilarity matrix of log-transformed read counts).</p

Results from pairwise comparisons of dispersion from the centroid between honey bee castes (PERMDISP based on Bray-Curtis dissimilarity matrix of read counts).

<p>P-values are Monte-Carlo estimates from 9,999 unrestricted permutations of the raw data.</p><p>Results from pairwise comparisons of dispersion from the centroid between honey bee castes (PERMDISP based on Bray-Curtis dissimilarity matrix of read counts).</p

Caste-Specific Differences in Hindgut Microbial Communities of Honey Bees (<i>Apis mellifera</i>)

<div><p>Host-symbiont dynamics are known to influence host phenotype, but their role in social behavior has yet to be investigated. Variation in life history across honey bee (<i>Apis mellifera</i>) castes may influence community composition of gut symbionts, which may in turn influence caste phenotypes. We investigated the relationship between host-symbiont dynamics and social behavior by characterizing the hindgut microbiome among distinct honey bee castes: queens, males and two types of workers, nurses and foragers. Despite a shared hive environment and mouth-to-mouth food transfer among nestmates, we detected separation among gut microbiomes of queens, workers, and males. Gut microbiomes of nurses and foragers were similar to previously characterized honey bee worker microbiomes and to each other, despite differences in diet, activity, and exposure to the external environment. Queen microbiomes were enriched for bacteria that may enhance metabolic conversion of energy from food to egg production. We propose that the two types of workers, which have the highest diversity of operational taxonomic units (OTUs) of bacteria, are central to the maintenance of the colony microbiome. Foragers may introduce new strains of bacteria to the colony from the environment and transfer them to nurses, who filter and distribute them to the rest of the colony. Our results support the idea that host-symbiont dynamics influence microbiome composition and, reciprocally, host social behavior.</p></div