Fig 1.
Map of locations from where flies were collected.
From each location (red circles) the microbiota of 7–10 male flies were established (A = 8; B = 7; C = 8; D = 10; E = 9; F = 9; G = 9; H = 10; I = 10; J = 10). Locations are designated with a letter (A-J). DNA was extracted from whole flies. In total 10 locations (dairy farms) were sampled throughout Denmark, where 4 locations (F-I) were in close proximity of each other (< 10 km). A GeoDanmark Basis map was downloaded from the Danish “Geodatastyrelsen”, October 2016, Styrelsen for Dataforsyning og Effektivisering. The figure is similar, but not identical to the original image, and is therefore for illustrative purposes only.
Fig 2.
Diversity measurements of the bacterial communities of houseflies sampled across location.
Boxplot displaying the observed number of OTUs (a), richness (b; Chao1), evenness (c; Shannon’s index) and biodiversity (d; Simpson’s index) per location (A-J) of sampling (n = 7–10). The boxplot bounds the interquartile range (IQR) divided by the median, the whiskers extend to 1.5x IQR beyond the box.
Fig 3.
Principal coordinate analysis (PCoA) of the housefly microbiota.
PCoA of unweighted UniFrac distances between samples. Samples are colored by location and designated as A-J. OTUs with an abundant (>0.1% of total reads in at least 1 sample) presence were included in the analysis.
Fig 4.
Composition and abundance of the housefly microbiota.
Heatmap (mean ± SD) representing the 20 bacterial classes (sorted by phylum) with the highest relative abundance. Samples are sorted by location.
Fig 5.
Barplot displaying number of abundant and core taxa of the housefly microbiota per taxonomic level.
The total number of abundant taxa was defined as >0.1% abundance in at least 1 sample (dark grey) and core taxa as occurring and abundant in 80% of all samples (grey). OTUs with an abundant (>0.1% of total reads in at least 1 sample) presence were included in the analysis.
Fig 6.
Phylogenetic tree and heatmap of selected families.
Heatmap displaying the abundant occurrence (present/non present) of the OTUs identified from each family, Enterobacteriaceae, Pseudomonadaceae, Campylobacteraceae, Staphylococcaceae, and Enterococcaceae. Samples are ordered via a UPGMA based phylogenetic tree based on their 16S rRNA gene consensus sequences. Some OTUs were only identified to family (f = family). OTUs with an abundant (>0.1% of total reads in at least 1 sample) presence were included in the analysis.