Document Type

Honors Thesis

Semester of Graduation

Spring 2026

Abstract

Over the course of embryonic development, the ectodermal cell layer gives rise to a vast array of neurons and glia patterned across the central nervous system (CNS). Neurulation and specification is achieved in the ectoderm through temporospatial patterns of transcription factor (TF) expression, many of which are conserved across evolutionary history. These conserved regulatory motifs allow the use of Drosophila melanogaster to study the mechanisms of neurodevelopment across the animal kingdom. The huckebein (hkb) gene encodes a conserved SP1/KLF TF known to play important roles in cell cycle regulation, tissue morphogenesis during tubular organ development, and gut specification in Drosophila. Hkb is present in specific neuroblasts during embryogenesis and is involved in glial specification. However, its overarching role in neurodevelopment remains largely unknown. Our analyses reveal severe neural defects in hkb mutant Drosophila embryos along the ventral nerve cord (VNC), the Drosophila equivalent of the spinal cord. Notably, human orthologs of hkb are associated with oncological, psychiatric, and developmental disorders. Vertebrate models show conserved expression in the developing CNS suggesting hkb may play a conserved role in neurogenesis, highlighting the importance of studying these SP1/KLF-associated defects. We characterized the role of hkb in the CNS by examining patterns of cell death along the VNC using immunohistochemistry for the apoptosis marker Drosophila caspase-1. We also identified the neural cell types that express hkb through the UAS-GAL4 system. Finally, we explored genetic interactions between hkb and three key transcriptional targets, zipper (encoding the myosin heavy chain), Neurexin IV (a septate junction component), and Stat92E (the transcription factor of the Drosophila JAK/STAT pathway), using in-situ hybridization and genetic interaction assays. Together, our data suggest that hkb is expressed in many neurons and glia, including perineurial glia, is vital to regulating VNC cell survival, and interacts with Neurexin IV.

Awardee Name

Benjamin Almond

Academic Major

Biological Sciences

Project Mentor

SeYeon Chung

Included in

Biology Commons

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