Susa, Emily2019-08-202019-08-202019-05https://hdl.handle.net/11299/206132University of Minnesota M.S. thesis. May 2019. Major: Integrated Biosciences. Advisor: Sara Zimmer. 1 computer file (PDF); v, 101 pages.Trypanosoma cruzi and Trypanosoma brucei are vector-borne protozoan parasites that cause devastating disease to humans and livestock in South America, North America and Africa. Both parasites have complex life cycles which involve a variety of different environments and nutrient sources within mammalian hosts and arthropod vectors. Transitioning between life cycle stages requires a transformation of morphology, replicative ability, and metabolism, which requires remodeling of mitochondrial and nuclear gene expression. To better understand the complicated genetic factors involved in life stage differentiation in these organisms, we have investigated several aspects of the regulation of gene expression through life stage transitions. In T. brucei, we investigated the role of a putative endoribonuclease, EEP1, on the transition from the mammalian life stage to the insect life stage. Our results indicate that EEP1 does not play a role in the differentiation process, and may serve an entirely unique function. In T. cruzi, we examined the mitochondrial genome which plays a crucial role in metabolism and has been shown to exhibit life-stage specific remodeling in related species. Mitochondrial genome regulation must occur post-transcriptionally in the form of RNA editing, translational control, and stability. Significant changes were detected in mature mRNA abundance between several life stages, and these differences appeared to be correlated with nutrient availability and replication status. Overall, both of these studies provide further understanding of the regulatory processes that govern life cycle transitions in trypanosome parasites.enMitochondriaParasiteRNATrypanosomaTrypanosomiasisThesis or Dissertation