Department or Program

Biological Chemistry


Most, if not all species on the planet serve as a habitat for one or more microbial symbionts. When considering this, the continued existence of these coupled interactions that often span across phylogeny and geographic proximity are especially notable since they indicate that these symbioses have an evolutionary benefit in maintaining viability within an ecosystem. This study sought to explore the potential role of ABC transporters, a large protein family found in every organism, in facilitating the introduction of algae of the genus Chlorella in the freshwater sponge species Ephydatia muelleri. It was thought that because ABC transporters are a major class of transport proteins responsible for cellular influx and efflux, they could be responsible in ensuring symbiont survival upon entering the host environment. In order to evaluate this hypothesis, sponges were grown and infected with algae after which RNA was harvested at multiple time points. qRT-PCR was then used to evaluate the levels of expression for multiple ABC transporters under differing experimental conditions, including heterozygous cross infections. Initial findings suggest that the downregulation of ABCC4 is directly involved in the establishment of the observed symbiosis, whereas it is less evident the role that ABCE1 plays. Additionally, these results there exists some mechanism for host promiscuity and symbiont recognition. There was also a bioinformatics portion that characterized the domains for both transporters for the first time in sponges. Further research using these findings could evaluate if these same findings carry over in establishing symbiotic relationships in other species.

Level of Access

Restricted: Embargoed [Open Access After Expiration]

First Advisor

Hill, April

Date of Graduation


Degree Name

Bachelor of Science

Number of Pages


Components of Thesis

1 pdf file


Available to all on Thursday, May 01, 2025