Everhart Lecture

Nematodes are the most abundant animal on the earth and occupy virtually every known niche and habitat, from steamy South American jungles to the seemingly barren Antarctic Dry Valleys. Though best known by the free-living model nematode, C. elegans, there are numerous nematode parasites, many of which cause human suffering directly through disease or indirectly through crop loss and damage.

Among nematode parasites is a unique group of lethal insect parasites that use pathogenic bacteria to kill their hosts. These are beneficial nematodes, commercially used across the globe as alternatives to chemical pesticides for controlling agriculturally damaging insects. It is unclear how even closely related species of insect parasitic nematodes can vary so greatly in the number and type of insect hosts they are capable of infecting and killing or how nematode parasites find their hosts, and it is on these questions that I have chosen to focus my research.

Being eyeless and earless, olfaction is the primary way nematodes interpret their environment. I have explored the host-seeking behavior of insect parasitic nematodes, including their unique ability to jump. All the parasitic species I have tested show a remarkable ability to detect and differentiate among potential hosts based on olfactory cues, though even closely related species differ in their odor preferences. I will discuss how comparative genomics of insect parasitic nematodes provides hypotheses and insight about differences in development, behavior, and ecology, as well as clues about differences in host range and specificity among parasites. Amid the tumult and hype that drives DNA sequencing technology forward, we are left wondering: what does a genome tell us abut the underlying differences between organisms? I will discuss what nematodes can teach us about the value of new genomes and how these microscopic animals have a major impact on biological discoveries.

A reception with refreshments will be served from 4:00 - 5:00pm before the event.

The Everhart Lecture Series is a forum to encourage interdisciplinary interaction among graduate students and faculty, to share ideas about recent research developments, problems and controversies, and to recognize the exemplary presentation and research abilities of Caltech's graduate students. Lecturers discuss scientific topics at a level suitable for graduate students and faculty from all fields while addressing current research issues.

Three graduate students out of all the nominees are selected to present their research during the Winter and Spring Terms.