Life Sciences Commons^™

Determining The Effects Of Mistranslating Transfer Rna Variants On Drosophila Melanogaster, Joshua R. Isaacson

Electronic Thesis and Dissertation Repository

Transfer RNAs (tRNAs) play a central role in translation as adaptor molecules between mRNA and protein. Variant tRNAs can cause the misincorporation of an amino acid into a growing polypeptide. Mistranslating tRNA variants are surprisingly common in humans but the effects of mistranslating tRNA variants on eukaryotic biology are poorly understood. My thesis aimed to create a model of tRNA-induced mistranslation using the fruit fly Drosophila melanogaster and characterize the effects of mistranslating tRNA variants on eukaryotic biology.

I first integrated a gene encoding a serine tRNA variant that induced proline-to-serine (P>S) mistranslation into the fly genome. Proteins isolated …

Recovery From Social Isolation In Drosophila: The Role Of Dopamine And The Autism-Related Gene Nlg3., Ryley T. Yost

Electronic Thesis and Dissertation Repository

Within a group, individuals establish their preferred distance from each other, or social space, a form of social behaviour. The resulting distance depends on the exchange of social cues from others that needs to be perceived and integrated within the organism’s neural circuitry. In humans, social spacing can be impaired in neuropsychiatric disorders such as autism and schizophrenia. When organisms are subject to social isolation, profound changes in social behaviour are observed in a variety of species from insects to mammals, including social space. However, the genetic and molecular mechanisms modulating a behavioural response to isolation and possible recovery remain …

Examining The Effect Of Knocking Down Dopamine Receptors In Fruitless Sexually Dimorphic Neurons On Social Spacing, Avneet A. Sahota

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Social behaviour is an individual's response to others within a group. From humans to mice to even fruit flies, social behaviour involves interactions with others and their ability to exchange information. Social spacing is a type of social behaviour which measures the distance between two organisms. It is a balance of attractive and repulsive cues which are influenced by genetics and by the external environment. However, individuals with disorders such as autism spectrum or Williams syndrome display abnormal social spacing as they are unable to understand social and non-social cues. Also, dopamine is a neurotransmitter that is a contributing factor …

Analysis Of The Chemotactic And Anti-Ovarian Response To Honeybee Queen Mandibular Pheromone (Qmp) And Its Constituent Components In Drosophila Melanogaster, Suhayr Solangi

Electronic Thesis and Dissertation Repository

Drosophila melanogaster can mimic qualities of honeybee altruism mediated by queen mandibular pheromone (QMP), a honeybee pheromone, which includes suppression of oogenesis and chemotactic attraction of males to sources of QMP. In this study, I assessed chemotaxis to the components of synthetic QMP (sQMP): the phenols; methyl-p-hydroxybenzoate (HOB) and 4-hydroxy-3-methoxyphenylethanol (HVA), and decenoic acids; 9-hydroxy-decenoic acid (9-HDA) and 9-oxo-decenoic acid (9-ODA). I found that the chemotactic response to these components is sexually dimorphic and they have complex interactions with one another. I conducted a screen to inhibit olfactory receptor neurons (ORN) using tetanus toxin (TeTx) and OrGAL4 drivers. Of the …

The Role Of H3k4 Methyltransferases In Drosophila Memory, Nicholas Raun

Electronic Thesis and Dissertation Repository

Gene transcription required for long-term memory requires the modification of histones. However, there are still many uncertainties about the identity and spatial expression of genes regulated by histone modifications during memory related processes. In this project I examined the role of Drosophila melanogaster methyltransferases Set1 and trx in courtship memory. Genetic knockdown of Set1 and trx in the mushroom body (MB) revealed that Set1 was necessary for short- and long-term memory, while trx was only required for long-term memory. Transcriptional profiling of MBs following trx-knockdown revealed expression changes in MB-enriched genes and genes involved in RNA processing. Among the …

Gene Expression Changes In The Mushroom Body Of Drosophila Melanogaster During A Time Course Of Long-Term Memory Formation And Maintenance, Spencer G. Jones

Electronic Thesis and Dissertation Repository

Long-term memory (LTM) requires gene transcription. However, there is still much to learn about which genes are transcriptionally regulated during LTM and the biological roles they play. Here, gene expression changes were characterized in Drosophila melanogaster over a time course of LTM formation and maintenance in neurons of the mushroom body (MB), a structure required for normal learning and memory. I identified 120 genes differentially expressed (q < 0.2, fold change > 1.3) 24h after LTM induction. Among these were 13 potential downstream targets for RNA localization by the known memory genes pumilo, staufen and oskar, several genes encoding chromatin regulators and seven genes with …

Determination Of The Phylogenetic Range Of Sex Combs Reduced Activity In Drosophila Melanogaster, Laura E. Garofalo

Electronic Thesis and Dissertation Repository

The homeotic selector (Hox) genes are required for body patterning in bilaterians. Sex combs reduced (SCR) is a HOX protein in Drosophila melanogaster with two activities: SCR^T1 and SCR^lab activity required for patterning the prothorax (T1) and labia, respectively. SCR^T1 is proposed to be conserved throughout bilaterians while the phylogenetic range of functional conservation of SCR^lab is comparatively unknown. The goal of this work was to elucidate the evolutionary time point at which SCR activity changed. CRISPR/Cas9 transgenesis was used to incorporate ɸC31 integrase recombination sites in Drosophila Scr. The ɸC31 integrase could …

Investigating The Functional Significance Of Evolutionarily Conserved Protein Motifs Of The Drosophila Melanogaster Hox Protein, Sex Combs Reduced, Lovesha Sivanantharajah

Electronic Thesis and Dissertation Repository

Bilaterans share a common anterior-posterior (A-P) axis that is patterned by the Homeotic selector (Hox) genes. In Drosophila melanogaster, Hox gene expression in spatially restricted domains along the A-P axis of the embryo determines segmental identity. Identifying the genetic mechanisms of HOX control of development is essential for understanding body patterning in animals. I identified and characterized the role of evolutionarily conserved protein domains of the HOX protein, Sex combs reduced (SCR), in protein function. SCR is required for establishing the identity of both the labial and prothoracic segments. To identify regions of functional importance, 15 Scr …