Theses and Dissertations

ORCID

https://orcid.org/0009-0002-8516-4719

Advisor

Brown, Matthew W.

Committee Member

Frederick, Spiegel W.

Committee Member

Folk, Ryan

Committee Member

Ballinger, Matthew

Date of Degree

12-12-2025

Original embargo terms

Visible MSU Only 1 year

Document Type

Dissertation - Campus Access Only

Major

Biological Sciences

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Arts and Sciences

Department

Department of Biological Sciences

Abstract

The work here is in the pursuit of discovering and describing new protists and the relationships between them. Protists are those eukaryotes which are not animals, plants, or fungi. Protists as an assemblage consist of multiple additional “kingdom-equivalent” groupings, some of which supersede the traditional kingdoms, which are termed supergroups. The supergroup Amoebozoa is dominated by amoeboid protist species and home to many complex behaviors which are the focus of the work presented here. From the grime in the cracks of sidewalks and between bricks of buildings we isolated three cultures of amoebae that did not match any prior morphological description. We studied these organisms with a multifaceted approach including light microscopy, fluorescence microscopy, scanning electron microscopy, transmission electron microscopy, and molecular data. Phylogenetic and phylogenomic analyses revealed that these three isolates belonged to two novel genera and species, which we named Kanabo kenzan and Parakanabo toge. Thorough morphological observations revealed an uncommon cell shape for their phylogenetic position, which furthers understanding of the evolutionary history of Amoebozoa. All these combined aspects set a high precedent for species description which I believe is essential moving forward in protistology. Some amoebae, termed slime molds, perform complex spore dispersal behavior by forming (usually macroscopic) fruiting bodies. Given their visibility to the unaided eye, they have been studied for hundreds of years. The historically poor understanding of protists combined with the shifting standards of taxonomy have plagued many of these groups with outstanding inaccuracies. With molecular data gathered from transcriptome sequencing and careful morphological observations I began to solve some of these issues. I have rightfully restored Ceratiomyxa porioides to species level and shed light on the complex speciation of the rest of the genus Ceratiomyxa. In addition, I presented the first molecular evidence to support a long-standing morphological hypothesis in the genus Cribraria. The hypothesis proposes that species of Cribraria are taxonomically circumscribed with high priority to spore color. I presented evidence to support this, defying almost all other morphological traits. By joining morphological descriptions with molecular data, I continue to uphold best practices in describing new species and exploring eukaryotic diversity.

Sponsorship (Optional)

NSF, Texas EcoLabs, Gordon and Betty Moore Foundation

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