Characterization of pollen and bacterial community composition in brood provisions of a small carpenter bee

Abstract

Many insects obtain gut microbes from their diet, but how a mother's foraging patterns influence the microbes found in her offspring's food remains an open question. To address this gap, we studied a bee that forages for pollen from multiple species of plants and may therefore acquire diverse bacteria from different plants. We tested the hypothesis that pollen diversity correlates with bacterial diversity by simultaneously characterizing these two communities in bee brood provisions for the first time. We used deep sequencing of the plant RBCL gene and the bacterial 16S rRNA gene to characterize pollen and bacterial diversity. We then tested for associations between pollen and bacterial species richness and community composition, as well as co-occurrence of specific bacteria and pollen types. We found that both pollen and bacterial communities were extremely diverse, indicating that mother bees visit a wide variety of flowers for pollen and nectar and subsequently bring a diversity of microbes back into their nests. Pollen and bacterial species richness and community composition, however, were not correlated. Certain pollen types significantly co-occurred with the most proportionally abundant bacteria, indicating that the plants these pollen types came from may serve as reservoirs for these bacteria. Even so, the overall diversity of these communities appears to mask these associations at a broader scale. Further study of these pollen and bacteria associations will be important for understanding the complicated relationship between bacteria and wild bees.

Long‐read DNA metabarcoding of ribosomal RNA in the analysis of fungi from aquatic environments

“…DNA metabarcoding is widely used in the study of microbial communities (Davison et al, ; Hamad et al, ; McFrederick & Rehan, ; Tedersoo et al, ; Wurzbacher et al, ; Yu et al, ), whereby one or more marker regions in the genome are PCR‐amplified and sequenced using a next‐generation sequencing (NGS) platform. Reads are quality‐filtered, and sequences are clustered according to sequence similarity into putative taxa (Operational Taxonomic Units = OTUs).…”

Linking pollen foraging of megachilid bees to their nest bacterial microbiota

“…On the other hand, solitary bee nests harbor highly diverse bacterial communities (Keller, Grimmer, & Steffan‐Dewenter, ; Lozo et al, ; McFrederick & Rehan, ; Mohr & Tebbe, ; Voulgari‐Kokota, Grimmer, Steffan‐Dewenter, & Keller, ). However, only few studies have dealt with their role in larval health (Keller et al, ; McFrederick, Vuong, & Rothman, ) or their acquisition routes (McFrederick et al, ; Voulgari‐Kokota, McFrederick, Steffan‐Dewenter, & Keller, ).…”

“…These should be able to secure transmission routes over multiple generations through active and passive transmission. Three possible mechanisms are active inoculation of nest structures (as in Kaltenpoth, Yildirim, Gürbüz, Herzner, & Strohm, ) including stored pollen, active inoculation of eggs (Hosokawa, Kikuchi, & Fukatsu, ), or passive transmission through imported materials and especially food sources (McFrederick & Rehan, ; McFrederick et al, ; Rothman et al, ).…”

“…Simultaneous examination of pollen composition and pollen microbiota from the nests of a wild bee species has shown covariation across different landscapes, even though the causality of this association was not clear (McFrederick & Rehan, ). Furthermore, the association between the pollen microbiota and the pollen composition in the nests of a single bee species suggested possible plant‐mediated host–microbe relationships (McFrederick & Rehan, ). However, the complex relationships in the plant–pollinator–microbe triangle are currently not well understood and multispecies studies are currently lacking.…”

Contaminants of emerging concern affect Trichoplusia ni growth and development on artificial diets and a key host plant

“…Because training set can influence these taxonomic assignments (78), BLASTN searches against NCBI's online Nucleotide Collection (nr/nt) and 16S ribosomal RNA sequences (Bacteria and Archea) databases (accessed 03/02/2017) were performed. Any mitochondria or chloroplast OTUs and other obvious contaminants (as determined by the blank controls) were removed from the dataset as in McFrederick and Rehan (62). We aligned the quality-filtered dataset using the pynast aligner (79) and the Greengenes database (76).…”