Date of Completion

5-10-2020

Embargo Period

5-6-2025

Keywords

Drosophila, Spermathecae, Secretion, Notch, Pannier

Major Advisor

Jianjun Sun

Associate Advisor

Akiko Nishiyama

Associate Advisor

Joanne Conover

Associate Advisor

Rahul N.Kanadia

Associate Advisor

Barbara Mellone

Field of Study

Physiology and Neurobiology

Degree

Doctor of Philosophy

Open Access

Campus Access

Abstract

The spermatheca is a sperm storage gland in the Drosophila female reproductive system that plays an evolutionarily conserved function: female sperm storage. Specialized secretory cells are formed within the spermatheca and produce essential secretions to attract and protect sperm in the female reproductive tract. Despite recognition of its important function, little is known about the genetic networks regulating the formation and function of the spermathecal secretory cell (SSC). In this thesis, I identified Gal4 tools that allow genetic manipulation at each stage of SSC lineage progression and also in the mature secretory cells. Then, I discovered Notch signaling regulates the binary cell fate determinations in the SSC lineage. In addition, I also found Notch signaling adapted different strength at different stages, and the Notch endocytic regulators, such as Numb, Rab5 and Deltex, showed distinct regulatory consequences on the suppression or activation of high Notch signaling and low Notch signaling. By the end of the SSC lineage, secretory cells are matured to produce secretions. Through microarray data mining, I found pannier, a gene encoding GATA-family transcription factor, is highly enriched in SSCs and found to be essential for spermatheca’s sperm storage function. Fluorescence based secretion tracing revealed that pnr-knockdown blocked the transportation of secretory product into the gland lumen. Collectively, this thesis reported Gal4 tools to study the development and function of SSCs, established the SSC lineage as a valuable model to study the Notch endocytic regulation, and discovered pnr is essential for secretions to be transported into spermatheca lumen.

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Available for download on Tuesday, May 06, 2025

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