Digital Commons Network^™

The Molecular Evolution Of Non-Coding Dna And Population Ecology Of The Spiny Softshell Turtle (Apalone Spinifera) In Lake Champlain, Lucas Edward Bernacki

Graduate College Dissertations and Theses

ABSTRACT

Spiny softshell turtles (Apalone spinifera) occur at the northwest limit of their range in Lake Champlain. This species, although widespread across North America, is listed as threatened in Vermont due to habitat destruction and disturbances of anthropogenic origin. The population of spiny softshell turtles in Lake Champlain is isolated from other North American populations and is considered as an independent management unit. Efforts to obtain information on the biology of spiny softshell turtles in Lake Champlain precede 1936 with conservation measures being initiated in 1987.

Methods of studying spiny softshell turtles in Lake Champlain have included direct …

Effects Of Hybridization And Life History Tradeoffs On Pathogen Resistance In The Harvester Ants (Pogonomyrmex), Yainna M. Hernaiz-Hernandez

Graduate College Dissertations and Theses

A fundamental challenge faced by all organisms is the risk of infection by pathogens that can significantly reduce their fitness. The evolutionary dynamic between hosts and pathogens is expected to be a coevolutionary cycle, as pathogens evolve by increasing their level of virulence and hosts respond by increasing their level of resistance. The factors that influence the dynamics of adaptation by pathogen and host in response to one another are not well understood. Social insects live in dense colonies in high-pathogen soil environments, making them an ideal model system to study the factors influencing the evolution of pathogen resistance. In …

Fgf8a Is Required For Proper Vascularization Of The Zebrafish Retina, Erin Wysolmerski

Graduate College Dissertations and Theses

Fibroblast growth factors (FGFs) are critical in many aspects of embryonic development and other cellular functions including apoptosis, cell adhesion, and proliferation. FGF8a, specifically, is known to initiate retinal ganglion cell (RGC) differentiation along with FGF3 early in retinal development (Martinez-Morales et al., 2005b). There has been little research into later roles for FGF8a in eye development. Here we show mRNA expression of fgf8a in the presumptive RGCs of 2 day-old zebrafish, past the time of RGC differentiation (28-48 hours)(Schmitt and Dowling, 1996). In addition, mRNA expression of putative receptor, FGFR1b, was localized outside the retina on the presumptive vasculature. …

Fixed Versus Plastic Partial Migration Of The Aquatic Macroinvertebrate, Mysis Diluviana, In Lake Champlain, Peter Thomas Euclide

Graduate College Dissertations and Theses

Partial migration, whereby populations consist of residents and migrants, is common among migrating organisms. Partial migration of aquatic organisms, however, remains largely under-studied even though many aquatic animals exhibit horizontal and vertical migrations during their lifetime. Macroinvertebrates of the genus Mysis exhibit diel vertical migrations (DVM). Some species have recently been observed to exhibit partial diel migrations where some individuals reside on the bottom throughout the night while others migrate into the water column. To test the hypothesis that individuals are fixed as residents or migrants, we compared demographic information and C and N isotope compositions of M. diluviana caught …

Meckelin Functions In The Guided Movement And Orientation Of Basal Bodies Prior To Duplication In Paramecium Tetraurelia, Tyler August Picariello

Graduate College Dissertations and Theses

Ciliopathies are a group of disorders that arise from ciliary dysfunction. Meckelin (MKS3 or TMEM67) is a conserved transmembrane protein found at the transition zone of ciliated cells. In humans MKS3 is one of 3 genes linked to the ciliopathy Meckel Syndrome. This disease is characterized by occipital meningioencephalocoele, polycystic kidneys, fibrotic changes to the liver, postnatal polydactyly and situs inversus.

Paramecium tetraurelia is a single celled ciliated eukaryote. Its surface is organized of a meshwork of cortical units that run the length of the cell. At the center of the cortical units are either one or two basal bodies. …

Polycystin-2 (Pkd2), Eccentric (Xnta), And Meckelin (Mks3) In The Ciliated Model Organism Paramecium Tetraurelia, Megan Smith Valentine

Graduate College Dissertations and Theses

Paramecium tetraurelia is a ciliated single cell used as a model organism for the study of ciliopathies. Ciliopathies are mammalian diseases involving the dysfunction of cilia, including cilia maintenance, construction, and signaling. P. tetraurelia and its cilia provides an excellent non-canonical system for the investigation and elucidation of proteins important for the structure, maintenance and function of cilia and ciliary beating. We utilize features of this cell such as its 1000's of cilia and highly organized and patterned cell surface to observe changes in swimming behavior or disruptions in the ordered cell surface which are not feasible in mammalian cells. …

Gene Expression Noise In Stress Response As A Survival Strategy In Fluctuating Environments, Javier Garcia-Bernardo

Graduate College Dissertations and Theses

Populations of cells live in uncertain environments, where they encounter large variations in nutrients, oxygen and toxic compounds. In the fluctuating environment, cells can sense their surroundings and express proteins to protect themselves against harmful substances. However, if the stressor appears infrequently or abruptly, sensing can be too costly or too slow, and cells cannot rely solely on it. To hedge against the sudden appearance of a stressor, cell populations can also rely on phenotypic diversification through bet-hedging. In bet-hedging, cells exploit noise in gene expression or use multistable genetic networks to produce an heterogeneous distribution of resistance-conferring protein levels. …