Date of Thesis



tspO (tryptophan-rich sensory protein) and tspO-like genes have been identified in various organisms, including cyanobacteria, mice, and humans. The gene sequences and protein functions are known to vary widely among different species. Some bacteria use TspO-like proteins to regulate pigmentation and protect against extreme light exposure. In humans, the TspO-like protein is involved in controlling cholesterol and iron in the body. This research attempted to understand more fully the functions and conditions that control the expression of the tspO gene in cyanobacteria. Using modern techniques in biotechnology to measure levels of tspO gene expression, two strains of bacteria (Nostoc punctiforme and Anabaena variabilis) were studied under differing light conditions and at various time intervals. The cultures originally grown in red light were then moved to green light and vice versa. Then the expression of the tspO cDNA was measured at different time intervals. Our hypothesis was that tspO expression would be impacted by the different light conditions, but tspO expression levels did not change significantly in any condition. Research such as this study on cyanobacteria may lead to more comprehensive research on different organisms.


cyanobacteria, tspO, chromatic acclimation, expression analysis, qPCR, Anabaena variabilis, Nostoc punctiforme

Access Type

Honors Thesis (Bucknell Access Only)

Degree Type

Bachelor of Science



First Advisor

Emily Stowe