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Title: Strain diversity and host specificity in a specialized gut symbiont of honeybees and bumblebees
Abstract

Host‐restricted lineages of gut bacteria often include many closely related strains, but this fine‐scale diversity is rarely investigated. The specialized gut symbiontSnodgrassella alvihas codiversified with honeybees (Apis mellifera) and bumblebees (Bombus) for millions of years.Snodgrassella alvistrains are nearly identical for 16SrRNAgene sequences but have distinct gene repertoires potentially affecting host biology and community interactions. We examinedS. alvistrain diversity within and between hosts using deep sequencing both of a single‐copy coding gene (minD) and of the V4 region of the 16SrRNAgene. We sampled workers from domestic and feralA. melliferacolonies and wild‐caughtBombusrepresenting 14 species. Conventional analyses of community profiles, based on the V4 region of the 16SrRNAgene, failed to expose most strain variation. In contrast, theminDanalysis revealed extensive strain variation within and between host species and individuals.Snodgrassella alvistrain diversity is significantly higher inA. melliferathan inBombus, supporting the hypothesis that colony founding by swarms of workers enables retention of more diversity than colony founding by a single queen. MostBombusindividuals (72%) are dominated by a singleS. alvistrain, whereas mostA. mellifera(86%) possess multiple strains. NoS. alvistrains are shared betweenA. melliferaandBombus, indicating some host specificity. AmongBombus‐restricted strains, some are restricted to a single host species or subgenus, while others occur in multiple subgenera. Findings demonstrate that strains diversify both within and between host species and can be highly specific or relatively generalized in their host associations.

 
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NSF-PAR ID:
10246431
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
Molecular Ecology
Volume:
25
Issue:
18
ISSN:
0962-1083
Page Range / eLocation ID:
p. 4461-4471
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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