Life Sciences Commons^™

Unbiased Automated Quantitation Of Ros Signals In Live Retinal Neurons Of Drosophila Using Fiji/Imagej, Prajakta Deshpande, Neha Gogia, Anuradha Venkatakrishnan Chimata, Amit Singh

Biology Faculty Publications

Numerous imaging modules are utilized to study changes that occur during cellular processes. Besides qualitative (immunohistochemical) or semiquantitative (Western blot) approaches, direct quantitation method(s) for detecting and analyzing signal intensities for disease(s) biomarkers are lacking. Thus, there is a need to develop method(s) to quantitate specific signals and eliminate noise during live tissue imaging. An increase in reactive oxygen species (ROS) such as superoxide (O2•-) radicals results in oxidative damage of biomolecules, which leads to oxidative stress. This can be detected by dihydroethidium staining in live tissue(s), which does not rely on fixation and helps prevent stress on tissues. However, …

Direct Evidence Of Missing Mepsps Using Ca2-Sensor Imaging, Petar Gajic

Biological Sciences

Following an action potential in the presynaptic neuron there is evoked release of neurotransmitter into the synapse which activates ionotropic transmembrane receptors on the postsynaptic membrane that cause depolarizations in voltage that get recorded as excitatory postsynaptic potentials (EPSPs). In the absence of an action potential there is spontaneous release of neurotransmitter that postsynaptically gets recorded as miniature excitatory postsynaptic potentials (mEPSPs). According to the quantal hypothesis, postulated by Bernard Katz, the mEPSPs are allor- none changes in potential caused by a single quantum of neurotransmitter, which when added up create EPSPs. Following studies have found that these two modes …

Collective Chemotaxis Of Retinal Neural Cells From Drosophila Melanogaster In Controlled Microenvironments, Stephanie Zhang

Dissertations and Theses

More than 172 million people are influenced by a retinal disorder that stems from either age-related or developmental causes. Of those, 1.5 million people endure a developmental retinal disorder. In the developing retina, neural cells undergo a series of highly complicated differentiation and migration process. A main cause of these diseases is abnormal collective migration of neural progenitors hindering the retinogenesis process. However, our grasp of collective migration and signaling molecules, critical to the developing retina, is incompletely understood. Understanding the molecular mechanisms, such as the fibroblast growth factor pathway, that regulate glial and neuronal migration provides decisive insights in …

Investigating Notch Signaling And Sequential Segmentation In The Fairy Shrimp, Thamnocephalus Platyurus, Sara Izzat Khalil

Senior Theses and Projects

Segmentation is a key feature of arthropod diversity and evolution. In the standard model for arthropod development, Drosophila melanogaster, segments develop simultaneously by a progressive subdivision of the embryo. By contrast, most arthropods add segments sequentially from a posterior region called the growth zone and in a manner similar to vertebrates.

Recent work, mainly focused on insects, suggests that Notch signaling might play a role in arthropods that segment sequentially. These studies document a potential regulatory similarity between sequentially segmenting arthropods and vertebrates. In vertebrates, somite formation involves a molecular oscillator that functions as a pacemaker, driving periodic expression …

Polygenic Resistance In The Highly Ddt-Resistant 91-R Strain Of Drosophila Melanogaster Involves Decreased Penetration, Increased Metabolism And Direct Excretion Of Ddt, Joseph P. Strycharz

Masters Theses 1911 - February 2014

Resistance to dichlorodiphenyltrichloroethane (DDT) in the 91-R strain of Drosophila melanogaster is extremely high compared to the susceptible Canton-S strain (>1500 times). Oxidative detoxification is involved in resistance but is not the only mechanism. Rates of DDT penetration, metabolism, and excretion were determined radiometrically between resistant 91-R and susceptible Canton-S strains. Contact penetration was ~1.5-times slower with 91-R flies compared to Canton-S flies. The 91-R strain had 13-fold more cuticular hydrocarbons, possibly resulting in penetration differences. DDT was metabolized ~33-fold more extensively by 91-R than Canton-S resulting in dichlorodiphenyldichloroethane (DDD), two unidentified metabolites and polar conjugates being formed in …

Metazoan Stress Granule Assembly Is Mediated By P-Eif2alpha-Dependent And -Independent Mechanisms, Natalie Farny, Nancy Kedersha, Pamela Silver

Natalie G. Farny

Stress granules (SGs) are cytoplasmic bodies wherein translationally silenced mRNAs are recruited for triage in response to environmental stress. We report that Drosophila cells form SGs in response to arsenite and heat shock. Drosophila SGs, like mammalian SGs, are distinct from but adjacent to processing bodies (PBs, sites of mRNA silencing and decay), require polysome disassembly, and are in dynamic equilibrium with polysomes. We further examine the role of the two Drosophila eIF2alpha kinases, PEK and GCN2, in regulating SG formation in response to heat and arsenite stress. While arsenite-induced SGs are dependent upon eIF2alpha phosphorylation, primarily via PEK, heat-induced …