The Science Seminar Series: September 23, 2010
Defensive Symbionts in Aphids
Dr. Kerry Oliver
University of Georgia-Athens Department of Entomology
Time: 4:00 -5:00pm
Aphids engage in symbiotic associations with a diverse assemblage of heritable bacteria. In addition to their obligate nutrient-provisioning symbiont, Buchnera aphidicola aphids may also carry one or more facultative symbionts. Facultative symbionts are not generally required for survival or reproduction but can invade and persist in host lineages by conferring benefits to hosts. Experiments on pea aphids (Acyrthosiphon pisum) have demonstrated that the facultative symbiont Hamiltonella confers protection against attack by the prevalent parasitoid Aphidius ervi by causing mortality to developing wasps. I will review the experimental evidence demonstrating a protective role for Hamiltonella, followed by a discussion of more recent work investigating the contribution of bacteriophages to the protective phenotype and to the maintenance of the tripartite symbiosis.