Publication Date

Spring 5-5-2022

Document Type


First Advisor

Swingley, Wesley

Degree Name

B.S. (Bachelor of Science)


Department of Biological Sciences


All cyanobacteria, which perform oxygenic photosynthesis on Earth, contain the photosynthetic pigment chlorophyll a (Chl a) that absorbs light in the violet and red region of the visible spectrum. Cyanobacteria of the Acaryochloris species, however, contain the rare photosynthetic pigment chlorophyll d (Chl d) that absorbs light in the far-red region. Chl d’s ability to absorb light in this region allows it to avoid competing with other photosynthetic organisms for light. Creating a photosystem that uses Chl d in plants would be of great use for agricultural land optimization, but requires knowledge of the biosynthetic pathways of Chl d. Previous research has been unsuccessful in understanding the production of Chl d, and our research seeks to fill this gap of knowledge.

The aim of this project is to generate transcriptomic data on the genetic expression of Chl d-producing cyanobacteria under far-red and white light and compare that data to the expression of Chl a-producing cyanobacteria under the same light conditions. The comparison of the genetic expressions of the samples will help to identify those genes responsible for Chl d production through differential gene expression analysis. Differential gene analysis is performed in a data processing pipeline that filters and normalizes the gene counts of our samples, fitting them to a model where we can test for differential expression. The development of this pipeline is ongoing, and we have tested model fitting and visualizations using published data concerned with the genetic expression of Chl d cultures.