Graduation Year


Graduation Month


Document Type

Professional Paper - Campus Access Only

School or Department

Biological Sciences, Division of



Faculty Mentor Department

Biological Sciences, Division of

Faculty Mentor

Scott Samuels


B. burgdorferi, Borrelia

Subject Categories



The spirochete Borrelia burgdorferi is the causative agent of Lyme disease, the most common vector-borne illness in the United States. The bacterium is maintained in nature through an enzootic cycle, rotating between a vertebrate host and a tick vector. After the tick absorbs the blood meal, the bacteria must find a different carbon and energy source to survive. Previous studies indicate that this new carbon and energy source is glycerol, a common three-carbon sugar present in the tick. In order to utilize this sugar, the bacterium induces a set of genes called the glp operon. glpD, the final gene in the operon, encodes an enzyme that shuttles glycerol into glycolysis, the main energy-extracting pathway in the cell. The expression of glpD is regulated differently than the other genes in the operon, and glpD can be transcribed into two different mRNAs. The bacterium can transcribe the full-length mRNA, which produces the entire enzyme, or a truncated version, which only includes the first two-thirds of the gene. In order to analyze the role of these gene products in the bacterium, a genetic approach was taken by deleting the glpD gene and assaying the phenotype of the mutant. Three different strains of B. burgdorferi were generated: a null glpD mutant, a glpD complement, and a truncated glpD mutant. Preliminary results suggest that the glpD mutant does not survive as well as the wild-type bacterium under starvation conditions, and that the truncated mutant has a motility phenotype. Future experiments will assess the mutants’ ability to survive in the presence and absence of glycerol and glucose in vitro, as well as their ability to survive in both ticks and mice.

Honors College Research Project




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