Researcher ORCID Identifier
https://orcid.org/0009-0009-3754-5403
Graduation Year
2025
Document Type
Open Access Senior Thesis
Degree Name
Bachelor of Arts
Department
W.M. Keck Science Department
Second Department
Neuroscience
Reader 1
Dr. Sandra Watson
Reader 2
Dr. Thomas Borowski
Terms of Use & License Information
Rights Information
© 2024 George C Blue
Abstract
Dopamine (DA) and dopaminergic transmission are highly conserved aspects of eukaryotic organisms that are implicated in both peripheral physiological processes and neurophysiological functioning. Many of these processes are conserved at the cellular and molecular level from Drosophila melanogaster to Homo sapiens, providing an excellent model organism for studying DA-related human diseases as well as typical dopaminergic functioning. A set of genes involved in DA synthesis and metabolism are clustered in the Drosophila genome around ddc, the gene that encodes for dopamine decarboxylase (Ddc). These genes form the Ddc gene cluster, and eight of them have experimentally been shown to increase levels of DA and/or DA metabolites in mutants. One of these genes, known as brain tumor (brat), is also implicated in neuroblast differentiation, particularly the determination of neuroblast cell fate. Because of the previously observed increases in DA in brat mutants, we sought to determine whether brat suppression increases activity and alters circadian rhythmicity by knocking down brat either pan-neuronally or in dopaminergic neurons and assaying for sleep and locomotor behavior. Our results suggest that knockdown of brat pan-neuronally displays a phenotype characterized by decreased activity and an unaltered circadian rhythm. Additionally, we sought to find a link between the increased DA phenotype and DA cell number in the central brains of brat mutants by quantifying DA cells as well as neuroblasts and their progeny in the central brains of third-instar larvae, hypothesizing that the increase in DA in mutants may be due to increases in DA neuron differentiation. Results suggested that brat mutants display increases in DA neurons as well as neuroblasts and their progeny. Whether this phenomenon is specific to DA neurons or occurs similarly in other neuron types remains unclear and warrants further investigation.
Recommended Citation
Blue, George; Watson, Sandra PhD; and Mistry, Rhea, "Uncovering a Novel Role for Drosophila brain tumor (brat) in Dopamine Regulation" (2025). Pitzer Senior Theses. 207.
https://scholarship.claremont.edu/pitzer_theses/207