The development of gene silencing strategies for plant parasitic nematodes

  • Johnathan Dalzell

Student thesis: Doctoral ThesisDoctor of Philosophy


This thesis has investigated various aspects of the RNA interference (RNAi) mechanism in two economically important plant parasitic nematodes (PRNs), the potato cyst nematode Globodera pallida and the root knot nematode Meloidogyne incognita. Much of the work contributing to this project has advanced our understanding of RNAi in these nematodes, and may also have broader implications for other parasitic nematode species. Although RNAi has been used widely to probe gene function in PRNs, this current body of work highlights a number of serious and potential issues which should be considered in future experimental designs.

Taken together, the data presented in this thesis: reveal that nematode parasites are broadly similar with respect to RNAi pathway complements; identify the off target impact of long dsRNAs in PPNs; identify the utility of siRNAs as triggers for gene silencing in PPNs; identify the first lethal siRNAs in any parasitic nematode; associate development processes in nematode parasites with non-coding RNAs; include the development of bioassays to delineate the phenotypic impacts of RNAi; identify a neuropeptide involved in host finding behaviour in a parasitic worm; reveal that siRNA and PCR amplicon positioning are key elements in the detection of a robust RNAi response; and, expose the potential for secondary siRNA and RNAi-pathway inhibitor involvement in RNAi responses in PPNs. These datasets combine to provide a significant advance in our understanding of gene silencing processes in PPNs and underscore the potential of PPNs as models for gene function studies in nematode parasites.
Date of AwardSept 2011
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorAaron Maule (Supervisor)

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