Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Life Sciences

Host-Acquired Virus Genes Support An Ancient Antiviral Role Of The Pirna Pathway In Dipterans, Rebecca Christian May 2023

Host-Acquired Virus Genes Support An Ancient Antiviral Role Of The Pirna Pathway In Dipterans, Rebecca Christian

Theses and Dissertations

Endogenous viral elements (EVEs) have been recently investigated as a source of transgenerational immune memory. These “viral fossils” are abundant in Aedes mosquitoes and partner with the host’s primary antiviral defense system, the RNA interference (RNAi) pathways. This partnership appears unique to mosquitoes, which encode an expansion of the Piwi endoribonucleases. To interrogate EVE-Piwi partnerships and their role in antiviral defense, I performed a comparative small RNA analysis of two naturally occurring EVE-virus pairs – one in the mosquito Aedes albopictus, and one in the midge Chaoborus americanus. Both express an EVE related to the nucleoprotein of their …


Molecular Evolution And Biogeography Of The New World Eptesicus Bats, Xueling Yi May 2022

Molecular Evolution And Biogeography Of The New World Eptesicus Bats, Xueling Yi

Theses and Dissertations

Molecular evolution refers to a broad field of studies ranging from microevolution (e.g., population genetics) to macroevolution (e.g., phylogeny), including the bridging field of phylogeography. In natural populations, molecular studies are also combined with biogeography that links biological diversity with geographic distributions to provide a comprehensive understanding of evolutionary processes. The field of molecular evolution has been largely advanced from early exploratory descriptions to statistical tests on biological hypotheses and integrative analyses using sophisticated modeling. However, studies of molecular evolution still face some unresolved questions and challenges, especially in non-model systems. For example, the application of new technology has largely …


Architecture Of Mate Choice Decisions In Enchenopa Treehoppers, Bretta Speck May 2022

Architecture Of Mate Choice Decisions In Enchenopa Treehoppers, Bretta Speck

Theses and Dissertations

Mate selection is one of the most important choices a female can make for herself and her offspring. Variation in mate choice decisions has consequences for the maintenance of and the diversity within a population and the promotion of divergence between populations. Mate choice decisions arise from the interaction of two main components: “mate preferences” (the relative attractiveness of a potential mate) and “choosiness” (the effort put into procuring a preferred mate). My dissertation analyzes the relationship between the components involved in female mate choice decisions in Enchenopa binotata treehoppers. I take a three-pronged approach. First, I investigated how E. …


Evolution And Biogeography Of Mesoamerican Small Mammals: With Focus On The Genus Handleyomys And Related Taxa, Ana Villalba Almendra Apr 2015

Evolution And Biogeography Of Mesoamerican Small Mammals: With Focus On The Genus Handleyomys And Related Taxa, Ana Villalba Almendra

Theses and Dissertations

Mesoamerica is considered a biodiversity hot spot with levels of endemism and species diversity likely underestimated. For mammals, the patterns of diversification of Mesoamerican taxa still are controversial. Reasons for this include the region's complex geologic history, and the relatively recent timing of such geological events. Previous studies, however, support the view that substantial migration between North (NA) and South America (SA) occurred prior or/and during the Great American Biotic Interchange (GABI) ~3.5 Ma. This was followed by repeated periods of isolation during Pleistocene climatic oscillations, which produced most of the diversification in the region. From a North American origin, …