RESEARCH EXPERIENCES FOR UNDERGRADUATES FROM RURAL AND TRIBAL COLLEGES
Investigator: Brian Darby, Ph.D., Associate Professor
Location: Department of Biology, Starcher Hall, University of North Dakota
Project Title: Genetic basis of nutrient-limited growth in grassland soil nematodes
Description: Nitrogen and phosphorous when added to soil and aquatic environments tend to stimulate the growth of organisms with disproportionately rapid growth rates. The Growth Rate Hypothesis postulates that rapid growth rates are constrained by cellular ribosome concentration and that nitrogen and phosphorous act as limiting nutrients. If true, this means there must be some gene (or genetic pathway) that facilitates rapid growth rates and places a high demand on nutrients like nitrogen and phosphorous. This research will test the hypothesis that rRNA gene copy number is the causative genetic mechanism for rapid growth rate in soil organisms using an integrative approach that combines ecological, genomic, and evolutionary methods. The rRNA operon is a strong candidate to be a genetic mechanism for the Growth Rate Hypothesis, as it codes for the vital and phosphorus-rich ribosomal RNA and appears in tandem repeats that vary in copy number between organisms. REU students will learn how to sample soil from a field research station, culture soil nematode isolates from the soil, clone the RNA Polymerase II and rRNA gene, and conduct real-time RT-qPCR to estimate the rRNA gene copy numbers in each isolate.