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Full-Text Articles in Life Sciences

Characterizing Mekk1: Candidate Behavioural Isolation Gene, Caryn Dooner Nov 2017

Characterizing Mekk1: Candidate Behavioural Isolation Gene, Caryn Dooner

Electronic Thesis and Dissertation Repository

Behavioural isolation can occur due to divergence in aspects of courtship and mating, and can contribute to reproductive isolation. The purpose of this study is to determine how a gene, Mekk1, contributes to female rejection behaviour between D. melanogaster and D. simulans. Unique polymorphisms were identified within D. simulans Mekk1 that could contribute to behaviour, most of which are non-coding. Both transcripts of Mekk1 appear to be expressed at similar levels in D. simulans and D. melanogaster. These data also indicate that Mekk1 may be expressed in a specific region of the brain called the mushroom body, …


Achilles Is A Circadian Clock-Controlled Gene That Regulates The Immune System And Its Rhythmicity In Drosophila, Jiajia Li Nov 2017

Achilles Is A Circadian Clock-Controlled Gene That Regulates The Immune System And Its Rhythmicity In Drosophila, Jiajia Li

Dissertations

Circadian clock is a transcriptional/translational feedback loop that drives the rhythmic expression of downstream mRNAs. Termed “clock-controlled genes,” these molecular outputs of the circadian clock orchestrate cellular, metabolic, and behavioral rhythms. As part of our on-going work to characterize key upstream regulators of circadian mRNA expression, we have identified a novel clock-controlled gene in Drosophila melanogaster, Achilles (Achl), which is rhythmic at the mRNA level in the brain and represses expression of immune response genes, especially anti-microbial peptides in the immune system. Achl knock-down in the brain dramatically elevates expression of crucial immune response genes, including IM1 …


Identification Of Genes That Maintain Behavioral And Structural Plasticity During Sleep Loss, Laurent Seugnet, Stephane Dissel, Matthew S. Thimgan, Lijuan Cao, Paul J. Shaw Oct 2017

Identification Of Genes That Maintain Behavioral And Structural Plasticity During Sleep Loss, Laurent Seugnet, Stephane Dissel, Matthew S. Thimgan, Lijuan Cao, Paul J. Shaw

Biological Sciences Faculty Research & Creative Works

Although patients with primary insomnia experience sleep disruption, they are able to maintain normal performance on a variety of cognitive tasks. This observation suggests that insomnia may be a condition where predisposing factors simultaneously increase the risk for insomnia and also mitigate against the deleterious consequences of waking. To gain insight into processes that might regulate sleep and buffer neuronal circuits during sleep loss, we manipulated three genes, fat facet (faf), highwire (hiw) and the GABA receptor Resistance to dieldrin (Rdl), that were differentially modulated in a Drosophila model of insomnia. Our results indicate …


The Genetic And Environmental Basis For Chc Biosynthesis In Drosophila, Heather Ke Ward Sep 2017

The Genetic And Environmental Basis For Chc Biosynthesis In Drosophila, Heather Ke Ward

Electronic Thesis and Dissertation Repository

Cuticular hydrocarbons (CHCs) are produced by insects and primarily used to prevent desiccation. In Drosophila, certain compounds have secondary roles as infochemicals that may act during courtship to influence mate choice. Certain CHCs may stimulate courtship with heterospecifics or act to repel conspecifics. The CHC profile produced by an individual is the result of the interaction between its genetic background and the environment, though the genes that underlie species differences in CHC production and how the environment can modulate the abundance of individual compounds within a species is not well known. Here, candidate gene CG5946 was found to be …


Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor Jun 2017

Cellular/Molecular Analysis Of Interspecies Sterile Male Hybrids In Drosophila, Rachelle L. Kanippayoor

Electronic Thesis and Dissertation Repository

Over time, genetic differences can accumulate between populations that are geographically separated. This genetic divergence can lead to the evolution of reproductive isolating mechanisms that reduce gene flow between the populations and, upon secondary contact, result in distinct species. The process of speciation is, thus, what accounts for the multitude of species that contribute to the rich biodiversity on Earth. Interspecies hybrid sterility is a postzygotic isolating mechanism that affects the development of hybrids, rendering them sterile. A notable trend, known as Haldane's Rule, describes that heterogametic individual (e.g. males in Drosophila) are more susceptible to sterility than homogametic …


Genetics Of Female Interspecific Mate Rejection In Species Of Drosophila, Ryan Calhoun May 2017

Genetics Of Female Interspecific Mate Rejection In Species Of Drosophila, Ryan Calhoun

Electronic Thesis and Dissertation Repository

Speciation can occur when accumulated differences in mating behavior force diverging species to remain reproductively isolated from one another. A key determinant of behavioural isolation is the evolution of female mating preferences that prevent interspecific males from mating. However, no individual genes involved in species-specific preferences of females have yet been identified. Using various genetic mapping techniques available for studying strains and species of Drosophila, I identify candidate genes involved in D. simulans female discrimination against D. melanogaster males. One candidate gene in particular, Katanin-60, was selected for further characterization. Katanin-60 is a gene encoding a microtubule severing …


Novel Effects Of Prefoldin Pathway On Intestinal Homeostasis Via Dietary Restriction In Drosophila Melanogaster, Jesse Simons May 2017

Novel Effects Of Prefoldin Pathway On Intestinal Homeostasis Via Dietary Restriction In Drosophila Melanogaster, Jesse Simons

Dissertations, Masters Theses, Capstones, and Culminating Projects

The field of medicine research is embroiled in a battle against aging. Particular focus is on the extension of lifespan and health-span. Lifespan duration is affected by many factors, one of which is the maintenance of the intestines of the organism. Homeostasis of the intestines is controlled by the regulation of intestine cell apoptosis and intestine cell proliferation. My research explores the role of two protein subunits found in a complex which may have possible functions in the regulation of these processes. The overall complex is formed from six subunit proteins, some of which are known to assist in other …


Cold Tolerance Of Third-Instar Drosophila Suzukii Larvae., Ruth Jakobs, Banafsheh Ahmadi, Sarah Houben, Tara D Gariepy, Brent J Sinclair Jan 2017

Cold Tolerance Of Third-Instar Drosophila Suzukii Larvae., Ruth Jakobs, Banafsheh Ahmadi, Sarah Houben, Tara D Gariepy, Brent J Sinclair

Biology Publications

Drosophila suzukii is an emerging global pest of soft fruit; although it likely overwinters as an adult, larval cold tolerance is important both for determining performance during spring and autumn, and for the development of temperature-based control methods aimed at larvae. We examined the low temperature biology of third instar feeding and wandering larvae in and out of food. We induced phenotypic plasticity of thermal biology by rearing under short days and fluctuating temperatures (5.5-19°C). Rearing under fluctuating temperatures led to much slower development (42.1days egg-adult) compared to control conditions (constant 21.5°C; 15.7days), and yielded larger adults of both sexes. …


Octopamine In Sexual Behavior, Ana Isabel Fernandez Jan 2017

Octopamine In Sexual Behavior, Ana Isabel Fernandez

Open Access Theses & Dissertations

Octopamine is a biogenic amine neuromodulator present in neuronal and non-neuronal tissues in invertebrates (Roeder, 1999). It modulates numerous physiological processes such as motivation, pheromone response, olfaction, ovulation, learning and memory. Octopamine together with its precursor tyramine have roles restricted only to invertebrates (Roeder, 1999). It is believed that octopamine is the invertebrate homolog of norepinephrine, a catecholamine present in mammals that acts as a neuromodulator in the sympathetic and central nervous systems. Both octopamine and norepinephrine are derived from the same amino acid tyrosine and are monoamine neurotransmitters. The main objective of this study is to understand the role …


Retrotransposons Are The Major Contributors To The Expansion Of The Drosophila Ananassae Muller F Element, William Leung, Sarah C. R. Elgin, Adam Haberman Jan 2017

Retrotransposons Are The Major Contributors To The Expansion Of The Drosophila Ananassae Muller F Element, William Leung, Sarah C. R. Elgin, Adam Haberman

Biology: Faculty Scholarship

The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (~5.2 Mb) is the smallest chromosome in Drosophila melanogaster, but it is substantially larger (>18.7 Mb) in Drosophila ananassae. To identify the major contributors to the expansion of the F element and to assess their impact, we improved the genome sequence and annotated the genes in a 1.4 Mb region of the D. ananassae F element, and a 1.7 Mb region from the D element for comparison. We find that transposons (particularly LTR and LINE retrotransposons) …


The Neuromodulatory Mechanisms That Monoamines Control Simple And Complex Behaviors, Paul Rafael Bermeo Sabandal Jan 2017

The Neuromodulatory Mechanisms That Monoamines Control Simple And Complex Behaviors, Paul Rafael Bermeo Sabandal

Open Access Theses & Dissertations

For my Dissertation, I worked on three projects in the fruit fly Drosophila melanogaster, which is a well-established genetic animal model. The first project (Chapter 1) is to elucidate the neural, cellular and molecular mechanisms underlying behavioral control named response inhibition. In this study, I identified that a particular subset of dopamine neurons, D1 dopamine receptors and the neural substrates crucial for response inhibition. Abnormal response inhibition is associated with the mental disorders including attention deficit hyperactivity disorder (ADHD), autism, schizophrenia, obsessive compulsive disorder, posttraumatic stress disorder and addiction, This study may help enhance our understanding the pathogenesis mechanisms of …