Exemplar Abstract for Hamiltonella defensa (sic) Moran et al. 2005 and Williamhamiltonella defendens corrig. Moran et al. 2005.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
George M Garrity
Keyword(s):  
Hamiltonella Defensa

scholarly journals Aphid Heritable Symbiont Exploits Defensive Mutualism

2017 ◽  
Vol 83 (8) ◽  
Author(s):  
Matthew R. Doremus ◽  
Kerry M. Oliver
Keyword(s):  
Fungal Pathogens ◽  
Acyrthosiphon Pisum ◽  
Pea Aphid ◽  
Single Infection ◽  
Community Members ◽  
Content Type ◽  
Defensive Mutualism ◽  
Potential Alternative ◽  
Hamiltonella Defensa ◽  
Alternative Routes

ABSTRACT Insects and other animals commonly form symbioses with heritable bacteria, which can exert large influences on host biology and ecology. The pea aphid, Acyrthosiphon pisum, is a model for studying effects of infection with heritable facultative symbionts (HFS), and each of its seven common HFS species has been reported to provide resistance to biotic or abiotic stresses. However, one common HFS, called X-type, rarely occurs as a single infection in field populations and instead typically superinfects individual aphids with Hamiltonella defensa, another HFS that protects aphids against attack by parasitic wasps. Using experimental aphid lines comprised of all possible infection combinations in a uniform aphid genotype, we investigated whether the most common strain of X-type provides any of the established benefits associated with aphid HFS as a single infection or superinfection with H. defensa. We found that X-type does not confer protection to any tested threats, including parasitoid wasps, fungal pathogens, or thermal stress. Instead, component fitness assays identified large costs associated with X-type infection, costs which were ameliorated in superinfected aphids. Together these findings suggest that X-type exploits the aphid/H. defensa mutualism and is maintained primarily as a superinfection by “hitchhiking” via the mutualistic benefits provided by another HFS. Exploitative symbionts potentially restrict the functions and distributions of mutualistic symbioses with effects that extend to other community members. IMPORTANCE Maternally transmitted bacterial symbionts are widespread and can have major impacts on the biology of arthropods, including insects of medical and agricultural importance. Given that host fitness and symbiont fitness are tightly linked, inherited symbionts can spread within host populations by providing beneficial services. Many insects, however, are frequently infected with multiple heritable symbiont species, providing potential alternative routes of symbiont maintenance. Here we show that a common pea aphid symbiont called X-type likely employs an exploitative strategy of hitchhiking off the benefits of a protective symbiont, Hamiltonella. Infection with X-type provides none of the benefits conferred by other aphid symbionts and instead results in large fitness costs, costs lessened by superinfection with Hamiltonella. These findings are corroborated by natural infections in field populations, where X-type is mostly found superinfecting aphids with Hamiltonella. Exploitative symbionts may be common in hosts with communities of heritable symbionts and serve to hasten the breakdown of mutualisms.

The Effect of Ants on the Population Dynamics of a Protective Symbiont of Aphids, Hamiltonella defensa

2012 ◽  
Vol 105 (3) ◽  
pp. 447-453 ◽  
Author(s):  
Daniel M. Erickson ◽  
Elizabeth A. Wood ◽  
Kerry M. Oliver ◽  
Ian Billick ◽  
Patrick Abbot
Keyword(s):  
Population Dynamics ◽  
Hamiltonella Defensa

scholarly journals The protector within: Comparative genomics of APSE phages across aphids reveals rampant recombination and diverse toxin arsenals

2020 ◽  
Author(s):  
Jeff Rouïl ◽  
Emmanuelle Jousselin ◽  
Armelle Coeur d’acier ◽  
Corinne Cruaud ◽  
Alejandro Manzano-Marín
Keyword(s):  
Comparative Genomics ◽  
Genome Evolution ◽  
Phylogenetic Analyses ◽  
Insect Species ◽  
Parasitoid Wasps ◽  
Valuable Resource ◽  
Variable Regions ◽  
New Genes ◽  
Endosymbiotic Bacteria ◽  
Hamiltonella Defensa

ABSTRACTPhages can fundamentally alter the physiology and metabolism of their hosts. While ubiquitous in the bacterial world, they have seldom been described among endosymbiotic bacteria. One notable exception in the APSE phage that is found associated with the gammaproteobacterial Hamiltonella defensa, hosted by several insect species. This secondary facultative endosymbiont is not necessary for the survival of its hosts but can infect certain individuals or even whole populations. Its infection in aphids is often associated with protection against parasitoid wasps. This protective phenotype has actually been linked to the infection of the symbiont strain with an APSE, which carries a toxin cassette that varies among so-called ”types”. In the present work, we seek to expand our understanding of the diversity of APSE phages as well as the relations of their Hamiltonella hosts. For this, we assembled and annotated the full genomes of 16 APSE phages infecting Hamiltonella symbionts across 10 insect species. Molecular and phylogenetic analyses suggest that recombination has occurred repeatedly among lineages. Comparative genomics of the phage genomes revealed two variable regions that are useful for phage typing. Additionally, we find that mobile elements could play a role in the acquisition of new genes in the toxin cassette. Altogether, we provide an unprecedented view of APSE diversity and their genome evolution across aphids. This genomic investigation will provide a valuable resource for the design and interpretation of experiments aiming at understanding the protective phenotype these phages confer to their insect hosts.

scholarly journals The whitefly‐associated facultative symbiont Hamiltonella defensa suppresses induced plant defences in tomato

2015 ◽  
Vol 29 (8) ◽  
pp. 1007-1018 ◽  
Author(s):  
Qi Su ◽  
Kerry M. Oliver ◽  
Wen Xie ◽  
Qingjun Wu ◽  
Shaoli Wang ◽  
...  
Keyword(s):  
Plant Defences ◽  
Hamiltonella Defensa

scholarly journals Horizontal Transfer of Bacterial Cytolethal Distending Toxin B Genes to Insects

2019 ◽  
Vol 36 (10) ◽  
pp. 2105-2110 ◽  
Author(s):  
Kirsten I Verster ◽  
Jennifer H Wisecaver ◽  
Marianthi Karageorgi ◽  
Rebecca P Duncan ◽  
Andrew D Gloss ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Natural Enemies ◽  
Larval Stage ◽  
Horizontal Transfer ◽  
Parasitoid Wasps ◽  
Cytolethal Distending Toxin ◽  
Toxin B ◽  
Genes Encoding ◽  
Hamiltonella Defensa

Abstract Horizontal gene transfer events have played a major role in the evolution of microbial species, but their importance in animals is less clear. Here, we report horizontal gene transfer of cytolethal distending toxin B (cdtB), prokaryotic genes encoding eukaryote-targeting DNase I toxins, into the genomes of vinegar flies (Diptera: Drosophilidae) and aphids (Hemiptera: Aphididae). We found insect-encoded cdtB genes are most closely related to orthologs from bacteriophage that infect Candidatus Hamiltonella defensa, a bacterial mutualistic symbiont of aphids that confers resistance to parasitoid wasps. In drosophilids, cdtB orthologs are highly expressed during the parasitoid-prone larval stage and encode a protein with ancestral DNase activity. We show that cdtB has been domesticated by diverse insects and hypothesize that it functions in defense against their natural enemies.

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