Wellcome Trust Post Doctoral Researcher
Room 411, Ashworth Laboratory
Telephone:+44 (0) 131 650 8684
2010- present: Post Doctoral Researcher, University of Edinburgh, UK
2005-2009 PhD University of Leicester
2002-2005 BSc. Honours, University of Leicester
I am interested in the molecular basis of variation within the invertebrate immune response and how this is maintained by host interactions with parasites (genotype x genotype (g x g) interactions) and the environment (genotype x environment (g x e) interactions).
Historically, mechanistic studies define invertebrate immunity as innate and non-specific and cannot explain the compelling evidence from ecological studies showing that invertebrates can respond with a high degree of specificity towards strains of a pathogen and induce trans-generational changes to immunity. Therefore, relatively little is known about the genes and molecular pathways generating specific innate immune responses.
My PhD aimed to begin bridging the gap between mechanistic and ecological perspectives of innate immunity by examining the molecular basis of immune specificity in the Bombus-Crithidia host-parasite system. I showed that immune gene expression mirrors the interaction effect previously found with indirect, ecological measures of immunity. This provides preliminary evidence that variation in the active immune response is associated with the specific g x g interaction between host and parasite.
Currently I am characterising the immune response of Daphnia magna during infection with the bacteria, Pasteuria ramosa and how g x g and g x e interactions affect the expression of immune genes. Identifying differential gene expression during these interactions may therefore provide clues as to the basis of host resistance or susceptibility to individual Pasteuria strains. In addition, infection can induce trans-generational changes in the immune response of offspring and I hope to investigate the molecular basis of this phenomenon in greater detail.
Riddell, C.E., Sumner, S., Adams, S., Mallon, E.B., Pathways to immunity: temporal dynamics of the bumblebee (Bombus terrestris) immune response against a trypanosomal gut parasite, Insect Molecular Biology 20 (4): 529-540
Riddell C., Adams S., Schmid-Hempel P., Mallon E.B., 2009 Differential expression of immune defences is associated with specific host-parasite interactions in insects. PLoS ONE 4(10): e7621
Riddell C., Mallon, E.B., 2005, Insect psychoneuroimmunology: Immune response reduces learning in protein starved bumblebees (Bombus terrestris), Brain, Behavior, and Immunity, 20(2): 135-138.