To access this work you must either be on the Smith College campus OR have valid Smith login credentials.

On Campus users: To access this work if you are on campus please Select the Download button.

Off Campus users: To access this work from off campus, please select the Off-Campus button and enter your Smith username and password when prompted.

Non-Smith users: You may request this item through Interlibrary Loan at your own library.

Alternative Title

Mechanisms of shell-building in the Arcellinid testate amoebae

Publication Date


First Advisor

Laura A. Katz

Document Type

Honors Project

Degree Name

Bachelor of Arts


Biological Sciences


Arcellinida, Amoebozoa, Testate amoeba, Eukaryotic microbes, Protists, Thecagenesis, Cellular trafficking, Gene expression, Transcriptomics


The Arcellinida (Amoebozoa) are a widespread order of freshwater testate amoeba. They play key roles in microbial ecosystems, including microbial food webs and nutrient cycling, and they are important bioindicators of ecosystem health and climate change. They are also engineering marvels, constructing intricate and diverse shells (tests) that have a wide range of morphologies and construction materials. Despite their importance, the Arcellinida remain severely understudied, and their cell biology is poorly characterized. In this study I aim to better understand shell-building in the Arcellinida by analyzing a set of candidate genes and assessing their differential expression in thecagenesis (i.e. shell building). I combine analysis of literature studies, microscopy, and transcriptomics to assess gene expression during shell-building. The results of this study implicate several genes in thecagenesis—notably I found that several gene families associated with membrane trafficking and cytoskeletal dynamics were differentially expressed. These data suggest that arcellinid gene families can be associated with cellular processes involved in thecagenesis. Future studies should examine these and additional gene families in more depth, as well as conduct functional characterization experiments, to better understand their role(s) in thecagenesis. These studies will increase our understanding of arcellinid physiology.


©2021 Naomi K. Ostriker. Access limited to the Smith College community and other researchers while on campus. Smith College community members also may access from off-campus using a Smith College log-in. Other off-campus researchers may request a copy through Interlibrary Loan for personal use.




60 pages : color illustrations. Includes bibliographical references (pages 48-54)