Project Summary

Title: Nematode-bacterial association at dynamic coastal habitat Virginia Coastal Reserve LTER


Supported by: US Army Research Laboratory and US Army Research Office under Contract number W911N7-08-1-0402



Summary: Remarkably complex key biological processes are carried out through interactions of a diverse array of biotic components. The metabolically versatile prokaryotes are functionally critical in the sediment environment. However, research dissecting prokaryotic diversity and its interactions with dominant, sediment dwelling invertebrate groups is currently lacking. Nematodes are ubiquitous, the most diverse and numerically dominant component of the

meiofauna, however their association with prokaryotes, though suggested to be widespread, is only characterized for some obvious cases. Lack of knowledge of the nematode-prokaryote associations is a serious impediment to progress in understanding key sediment processes. Here we hypothesize that nematodes and bacteria maintain specific associations, and we propose to test it in the framework of rich background information at a Long Term Ecological Research (LTER) site as part of the Virginia Coastal Reserve (VCR).

We intend to employ both traditional, morphological and modern, molecular methods in

three consecutive phases, each one-year long.

1. Taxa discovery (Year 1): Identify nematode taxa to the genus level and selectively identify ten taxa to species level based on morphological characteristic features. We will select the ten taxa based on their numerical dominance, representation of major divergent evolutionary lineages and differing stoma morphology.

2. Imaging of nematodes and the discovery of associations (Year 2): Nematode-bacterial

associations will be explored and identified from five environmentally diverse sites. The ten diverse and numerically dominant nematode species identified morphologically will be imaged and studied through sequencing phylogenetically informative marker genes. For the associated bacteria, we will use traditional methods (plating, isolation, enrichment) and molecular approaches (Denaturing Gradient Gel Electrophoresis; DGGE) to identify and characterize species-specific associations.

3. Selectively sequence bacteria and complete the DGGE work (Year 3).


Student Training and Strengthening Infrastructure: We plan to train and involve one graduate and three undergraduate students from underrepresented groups. To ensure student success, the training module will be effected through a comprehensive & collaborative framework including one-to-one mentoring where both the PI and the Co-PI will mentor the four students in a model where each student will have one primary and one secondary mentor, visit to regional graduate programs, training in a research university, participation in regional and national conferences & student preparation for standardized tests. Through faculty training, we plan to lay the foundation in the field of Bioinformatics at Elizabeth City State University. The microscopes we request will help address the current critical equipment and infrastructural needs of the department and school. We plan to integrate these proposed activities as part of ongoing core.



Funded by Army Research Office, US Department of Defense.