Life Sciences Commons^™

Effects Of Osmotic Stress On Oxygen Consumption Of Drosophila Cells (Kc167), Ali A. Ahmed, Rajib Hassan, Michael A. Menze

The Cardinal Edge

This article investigates the effect of osmotic stress on a drosophila cell line called Kc167.

The embryonic-derived fly (Drosophila melanogaster) cell line, Kc-167, was employed as a model for water-stress sensitivity in Arthropods. Like mammalian cells, cells derived from the fruit fly contain the same basic set of membranous components found in all eukaryotic cells. A series of experiments were conducted to characterize the mitochondrial repones of Kc167 cells to water stress. Precisely, the oxygen flux in a sealed respirometer chamber containing Kc167 cells was measured under hyperosmotic and control conditions. Mitochondrial uncouplers were used in some experiments for intact …

Characterization Of The Immune Deficiency Pathway During Female Meiosis In Drosophila Melanogaster, Sarah Mashburn

College of Science and Health Theses and Dissertations

Organisms can defend against pathogens by significantly increasing the diversity of their progeny, so that some progeny are more likely to survive infection. This led to the prediction that infection should cause an increase in recombination rates which was seen in a previous study. However, the mechanism that regulates recombination rates in response to infection is not understood and in that study they did not provide a mechanism for how that can occur. In an RNAi screen, our lab found the gene mustard (mtd) is required for normal recombination rates. This gene was previously shown to be part of the …

Regulation Of The Wnt/Wingless Receptor Lrp6/Arrow By The Deubiquitylating Complex Usp46, Zachary T. Spencer

Dartmouth College Ph.D Dissertations

The evolutionarily conserved Wnt/Wingless signal transduction pathway is critical for the proper development of all animals and implicated in numerous diseases in adulthood. Upon binding of the Wnt/Wingless ligand, a cascade of events culminates in inactivation of the destruction complex, a negative regulator of the pathway, and the subsequent formation of singalosomes which mediate pathway activation. A critical component of signalosome formation is the Wnt/Wingless receptor LRP6/Arrow. Upon canonical pathway activation, LRP6/Arrow undergoes activation via phosphorylation by several kinases and complexes with another Wnt/Wingless receptor Frizzled, along with several cytoplasmic components. While many studies have investigated the regulatory mechanisms of …

The G-Signaling Protein Rcp Controls The Polarized Basement Membrane Deposition In Epithelial Cells, Rebecca M. Brnot

Honors Capstones

Epithelial tissues are the most common type of tissue in the human body, forming the outer layer of the skin and most organs. They are composed of epithelial cells and rely heavily on their cellular architecture, which is organized by an apical-basal polarity, for their function. One critical component for the establishment and maintenance of the epithelial cell architecture is the proper placement of the basement membrane. The basement membrane is a specialized sheet within the extracellular matrix that lines the basal side of epithelial cells, and there is a biological pathway that is responsible for the proper placement of …

An In-Depth Study Of Border Cell Migration Within Drosophila Melanogaster, Leif R. Verace

Honors Capstones

Cell migration plays a key role in many biological processes including embryonic development, tissue morphogenesis, and the metastasis of cancer cells; thus, understanding how this behavior works is highly important. To study cell migration, we use the process of border cell (BC) migration in Drosophila melanogaster, which sees a cluster of cells migrate through a multicellular structure known as the egg chamber found in the Drosophila ovary. Here, I will describe my results in studying the role of a particular kinesin-like gene, CG14535, in BC migration. Through analysis of a mutant for this gene (labelled KC53), RNAi …

Transcriptome Profile In Drosophila Kc And S2 Embryonic Cell Lines, Daniel Klonaros, Jacqueline M. Dresch, Robert A. Drewell

Biology

Drosophila melanogaster cell lines are an important resource for a range of studies spanning genomics, molecular genetics, and cell biology. Amongst these valuable lines are Kc167 (Kc) and Schneider 2 (S2) cells, which were originally isolated in the late 1960s from embryonic sources and have been used extensively to investigate a broad spectrum of biological activities including cell-cell signaling and immune system function. Whole-genome tiling microarray analysis of total RNA from these two cell types was performed as part of the modENCODE project over a decade ago and revealed that they share a number of gene expression features. Here, we …

Understanding The Relationship Between B Chromosomes And Nondisjunction In Drosophila Melanogaster, Ayushi Patel

Honors Scholar Theses

B chromosomes are supernumerary, heterochromatic genetic elements that are found in hundreds of different plant and animal species. Recently, B chromosomes were discovered in a stock of Drosophila melanogaster and are carried at a high copy number of 10-12 B chromosomes per cell. B chromosomes are not known to carry any active genes, but when placed in a wild-type genetic background, they cause a significant increase in the frequency of chromosome 4 missegregation during meiosis. This project aimed to understand the relationship between a female’s B chromosome copy number and how often she passes on too many (or too few) …

Measuring Energy Demands Of Dynamic Remodeling Events During Embryogenesis In Live Drosophila Embryos, Grayson Young

Biological Sciences Undergraduate Honors Theses

Embryonic development is a complex process requiring dynamic cell movements to create complex tissue structures. We assume that these embryonic dynamic remodeling events are highly energy intensive and that this energy expenditure is mediated by mitochondria. However, this has been difficult to demonstrate in live embryos. Convergent extension of the Drosophila neuroectoderm is a promising system to study the bioenergetics of tissue remodeling because it changes from a static to a dynamically remodeling tissue with temporal precision. We hypothesize that the switch from static to dynamic development at the onset of convergent extension will be accompanied by an increase in …

Validating A New In Vivo Model To Study Als, Izabela J. Cimachowska

Student Theses and Dissertations

Buildup of oxidative stress and mitochondrial dysfunction are well known characteristics of both sporadic and hereditary amyotrophic lateral sclerosis (ALS). While both forms of the disease seem to arise from common cellular dysfunction, the genetic disease is studied to a much greater extent. Engineering novel animal models of the sporadic form of the disease is crucial for development of druggable targets to treat ALS and understand the underlying mechanisms. Interestingly, accumulation of oxidative stress by exacerbated emission of reactive oxygen species (ROS) from presynaptic mitochondria is a hallmark of both hereditary and sporadic ALS. Previous work by our laboratory showed …

Impacts Of Bacterial Evolution On Host Lethality In Drosophila, Andrew Preston

College of Arts & Sciences Senior Honors Theses

Evolution is the process by which species change their genetic traits, such as the pathogenicity of bacteria, over time in response to changes in their environment. Although the genetic mechanisms underlying many evolutionary processes have been revealed, it is still not well understood how opportunistic pathogens, such as Pseudomonas aeruginosa, become virulent. The overall goal of this thesis is to test the Coincidental Evolution Hypothesis, which proposes that the virulence of opportunistic pathogens evolves coincidentally as a by-product of their interaction with their natural predators. I hypothesized that the virulence of ancestral Pseudomonas aeruginosa changes over time if it co-evolves …

Effects Of Actin-Destabilizing Drugs On Motor Function In Drosophila Melanogaster, Caden Sullivan

Honors Theses

Actin dynamics influence many cellular processes including neural connectivity and function. One way to better understand and study the regulation of these dynamics is to manipulate actin dynamics and observe the effects in motor function as a proxy to changes on the neuromuscular junctions in developing neural tissue. On that line, this investigation hypothesized that changing the actin dynamics during development via drug manipulation results in observable effects in locomotion. One of the common actin regulatory drugs used throughout the literature includes Latrunculin A, which was used in this study. Methods included applying this actin destabilizing drug on developing wildtype …

Expression Of Htyr In Drosophila As A Novel Model Of Parkinson’S Disease, Madeleine Callan

Scripps Senior Theses

Parkinson’s disease is a debilitating and often deadly neurodegenerative disease affecting a growing and large population. Its etiology has long remained elusive, and because no other organisms have Parkinsonian-like diseases, it is difficult to study PD using model organisms. Neuromelanin (NM), an insoluble melanin synthesized in the dopaminergic synthesis pathway in DA neurons, has recently been implicated in PD as a major causal factor. At high levels in DA lysosomes, it functions as a proteostatic pathway inhibitor–blocking dopaminergic neurons from breaking down harmful molecules until the lysosomes eventually degenerate as well as triggering autophagy, inflammation, and total neurodegeneration. Recently, neuromelanin …

The Role Of Cort And Anaphase Promoting Complex/Cyclosome (Apc/C) In Drosophila Sex Determination And Meiosis, Abuzar Sikander Malik

Electronic Theses and Dissertations

The E3 ubiquitin ligase, APC/C, is essential for the completion cell cycle; along with its co-activators it allows mitotic exit and maintenance of G1. APC/C marks various substrates with ubiquitin chains; marked substrates are subsequently destroyed via the 26S proteasome pathway. Cort is a Drosophila female meiosis specific activator of APC/C. Cort works within meiosis in conjunction with Fzy to mediate Securin and cyclin destruction. A C-terminal IR-tail motif and a N-terminal C-box support Cort-APC/C interaction, whereas short motifs like D-box and KEN-box on the target protein impart substrate recognition to Cort. Cort expression is tightly controlled in the female …

Characterizing The Dynamic Localization Of Cmi In Early Drosophila Development, Asra Habibullah

Master's Theses

The COMPASS-like family of lysine methyltransferases, MLR/MLX complexes, are epigenetic regulators that are essential for normal development through the methylation of the fourth lysine residue on histone 3 (H3K4), a universal epigenetic mark associated with active transcription. This family of complexes is highly conserved from yeast to mammals and the genes encoding the human MLR complexes have been associated with various developmental diseases and cancers (Dingwall and Fagan, 2019). In D. melanogaster, the enzymatic methyltransferase core of this complex is composed of two proteins: Cara Mitad (Cmi, also known as Lpt) and Trithorax-related (Trr). Although these proteins have been shown …

Genetic And Environmental Contributions To Wolbachia-Induced Cytoplasmic Incompatibility, Kelley Van Vaerenberghe

Graduate Student Theses, Dissertations, & Professional Papers

Maternally-transmitted Wolbachia infect the cells of most insect species, but their frequencies in host populations vary. While much of their success can be attributed to their ability to manipulate host reproduction, these manipulations are context-dependent, varying due to several biotic and abiotic factors. Wolbachia’s most common manipulation, cytoplasmic incompatibility (CI), is a conditional sterility phenotype where male-female host compatibility depends on their infection status. Specifically, CI occurs when infected males produce modified sperm that cause increased embryonic lethality unless the female carries a similar infection. Rescuing their eggs from CI increases the relative fitness of infected females, promoting Wolbachia spread …