Skip to Main Content
Dynamic Acquisition and Loss of Dual-Obligate Symbionts in the Plant-Sap-Feeding Adelgidae (Hemiptera: Sternorrhyncha: Aphidoidea)Author(s): Carol D. von Dohlen; Usha Spaulding; Kistie B. Patch; Kathryn M. Weglarz; Robert G. Foottit; Nathan P. Havill; Gaelen R. Burke
Source: Frontiers in Microbiology
Publication Series: Scientific Journal (JRNL)
Station: Northern Research Station
Download Publication (4.0 MB)
DescriptionSap-sucking insects typically engage in obligate relationships with symbiotic bacteria that play nutritional roles in synthesizing nutrients unavailable or in scarce supply from the plant-sap diets of their hosts. Adelgids are sap-sucking insects with complex life cycles that involve alternation between conifer tree species. While all adelgid species feed on spruce during the sexual phase of their life cycle, each adelgid species belongs to a major lineage that feeds on a distinct genus of conifers as their alternate host. Previous work on adelgid symbionts had discovered pairs of symbionts within each host species, and unusual diversity across the insect family, but left several open questions regarding the status of bacterial associates. Here, we explored the consistency of symbionts within and across adelgid lineages, and sought evidence for facultative vs. obligate symbiont status. Representative species were surveyed for symbionts using 16S ribosomal DNA gene sequencing, confirming that different symbiont pairs were consistently present within each major adelgid lineage. Several approaches were used to establish whether symbionts exhibited characteristics of long-term, obligate mutualists. Patterns of symbiont presence across adelgid species and diversification with host insects suggested obligate relationships. Fluorescent in situ hybridization and electron microscopy localized symbionts to bacteriocyte cells within the bacteriome of each species (with one previously known exception), and detection of symbionts in eggs indicated their vertical transmission. Common characteristics of long-term obligate symbionts, such as nucleotide compositional bias and pleomorphic symbiont cell shape were also observed. Superimposing microbial symbionts on the adelgid phylogeny revealed a dynamic pattern of symbiont gains and losses over a relatively short period of time compared to other symbionts associated with sap-sucking insects, with each adelgid species possessing an older, "senior" symbiont and a younger "junior" symbiont. A hypothesis relating adelgid life cycles to relaxed constraints on symbionts is proposed, with the degradation of senior symbionts and repeated acquisition of more junior symbionts creating opportunities for repeated colonization of new alternate-conifer hosts by adelgids.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, email@example.com if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
Citationvon Dohlen, Carol D.; Spaulding, Usha; Patch, Kistie B.; Weglarz, Kathryn M.; Foottit, Robert G.; Havill, Nathan P.; Burke, Gaelen R. 2017. Dynamic Acquisition and Loss of Dual-Obligate Symbionts in the Plant-Sap-Feeding Adelgidae (Hemiptera: Sternorrhyncha: Aphidoidea). Frontiers in Microbiology. 8: 439-. 15 p. https://doi.org/10.3389/fmicb.2017.01037.
Keywordsbacterial symbionts, complex life cycles, dual symbionts, insects, host alternation, symbiont replacements
- Gut bacteria of bark and wood boring beetles
- Microorganisms associated with production lots of the nucleopolyhedrosis virus of the gypsy moth Lymantria dispar (Lep.: Lymantriidae)
- Diversity of Hindgut Bacterial Population in Subterranean Termite, Reticulitermes flavipes
XML: View XML