Honors College Theses

Publication Date



Biology (B.S.B.)

Document Type and Release Option

Thesis (open access)

Faculty Mentor

Dr. Quentin Q. Fang


The American dog tick Dermacentor variabilis is a hard body, 3-host tick that relies on the blood of small and large mammals to satisfy its metabolic demands. The excess iron consumed in its blood diet can cause cellular damage through oxidation. Ticks rely on the ferritin protein to metabolize iron. For this reason, it is important to further characterize the ferritin gene. After extracting DNA from D. variabilis ticks, the suspected ferritin gene was amplified through polymerase chain reaction (PCR) and purified. The putative ferritin DNA fragment was inserted into plasmids and isolated in a long PCR length gene cloning. Overlapping DNA fragments were sequenced from the genomic DNA of the entire ferritin coding region and aligned with cDNA of the D. variabilis ferritin heavy chain homologue (HCH) gene to determine the intron/exon structure. The results revealed that the D. variabilis ferritin gene coding region has three exons and two introns. The entire D. variabilis ferritin (HCH) gene coding region is 3,805 base pairs long. The three exons are 106 bp, 277 bp, and 135 bp in length, respectively, with a G+C content around 53%. The two introns are 2268 and 1019 bp in length, with an average A+T content of 56%. It is hypothesized that the long first intron of the D. variabilis ferritin gene might play a role in alternative splicing and possibly also ferritin gene expression.