Author ORCID Identifier

Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Arts and Sciences



First Advisor

Dr. Douglas Harrison


The Drosophila micropyle is a conserved formation utilized to allow sperm passage past the robust eggshell structure for fertilization. Micropyle formation follows a unique acellular tubulogenesis method where it is secreted and shaped by specialized follicle cells including the border cells and polar cells. In late oogenesis, the polar cells form extensions that are necessary to create the micropyle pore through which sperm enters. Previous work established that polar cell extension presence is required for micropyle pore formation. We investigated temporal requirements of extensions throughout chorion deposition and found extensions are required during the beginning and middle of choriogenesis, but not the end, suggesting that extensions are only necessary to form the inner pore structure. We also investigated polar cell extensions involvement in formation of sperm-attracting micropyle surface glycoproteins. It was found that polar cell extensions are not involved, but some component of the border/polar cell cluster is seemingly involved in their formation. Finally, we investigated polar cell apoptosis requirements at the end of oogenesis and found that polar cell apoptosis is required to clear the micropyle pore for sperm entry. These results support our placeholder model of tube formation and contribute to the comprehension of polar cell functions.

Digital Object Identifier (DOI)