The Microbial Associates and Putative Venoms of Seed Chalcid Wasps (Hymenoptera: Torymidae: Megastigmus)

dc.contributor.authorPaulson, Amber Rose
dc.contributor.supervisorPerlman, Steven John
dc.contributor.supervisorAderkas, P. von
dc.date.accessioned2013-12-20T23:19:14Z
dc.date.available2013-12-20T23:19:14Z
dc.date.copyright2013en_US
dc.date.issued2013-12-20
dc.degree.departmentDepartment of Biologyen_US
dc.degree.levelMaster of Science M.Sc.en_US
dc.description.abstractConifer seed-infesting chalcids of the genus Megastigmus (Hymenoptera: Torymidae) are important forest pests. At least one species, M. spermotrophus Wachtl, has been shown to be able to manipulate the seed development of its host, Douglas-fir (Pseudotsuga menziesii) in remarkable ways, such as redirecting unfertilized ovules that would normally abort. The mechanism of host manipulation is currently unknown. Microbial associates and venoms are two potential mechanisms of host manipulation. Microbial associates are emerging as an important player in insect-plant interactions. There is also evidence that venoms may be important in gall-induction by phytophagous wasps. PCR and 16S rRNA pyrosequencing was used to characterize the microbial associates of Megastigmus and transcriptomic sequencing was used to identify putative venoms that were highly expressed in female M. spermotrophus. The common inherited bacterial symbionts Wolbachia and Rickettsia were found to be prevalent among several populations of Megastigmus spp. screened using a targeted PCR approach. A member of the Betaproteobacteria, Ralstonia, was identified as the dominant microbial associate of M. spermotrophus using 16S rRNA pyrosequencing. The transcriptome of M. spermotrophus was assembled de novo and three putative venoms were identified as highly expressed in females. One of these putative venoms, Aspartylglucosaminidase, (AGA) appears to have originated through gene duplication within the Hymenoptera and has been identified as a major venom component of two divergent parasitoid wasps. AGA was identified as a promising candidate for further investigation as a potential mechanism of early host manipulation by M. spermotrophus.en_US
dc.description.proquestcode0353en_US
dc.description.proquestcode0410en_US
dc.description.proquestcode0715en_US
dc.description.proquestemailapaulson@shaw.caen_US
dc.description.scholarlevelGraduateen_US
dc.identifier.urihttp://hdl.handle.net/1828/5103
dc.language.isoenen_US
dc.rights.tempAvailable to the World Wide Weben_US
dc.subjectvenomen_US
dc.subjecttranscriptomeen_US
dc.subjectmicrobial associatesen_US
dc.subjectnext generation sequencingen_US
dc.subjectMegastigmus spermotrophusen_US
dc.subjectDouglas-fir seed chalciden_US
dc.subjectRalstoniaen_US
dc.subjectWolbachiaen_US
dc.subjectRickettsiaen_US
dc.subjectMicrosporidiaen_US
dc.subjectendosymbionten_US
dc.titleThe Microbial Associates and Putative Venoms of Seed Chalcid Wasps (Hymenoptera: Torymidae: Megastigmus)en_US
dc.typeThesisen_US

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