Mechanisms of germ cell development in Drosophila oogenesis.

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Taylor D. Hinnant (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: Germ cell development requires interplay between factors that control cell fate and division. Early in their development , germ cells are an interconnected group of mitotically dividing cells. Key regulatory events then lead to the specification of mature gametes , and is also marked by the switch to a meiotic cell cycle program. Though the events required for gamete specification and the regulation of meiosis are well understood , how each of these events are coordinated during development remain unclear. The adult Drosophila ovary continuously produces germ cells throughout the organism's lifetime , but many of the cellular processes that occur during mammalian gamete development are conserved. Drosophila ovaries produce oocytes through the actions of asymmetrically germline stem cells (GSCs) , which give rise to a differentiated daughter cell (the cystoblast) , while self-renewing to replenish the stem cell pool. The cystoblast divides four times with incomplete cytokinesis; fifteen daughter cells give rise to endocycling nurse cells , while the remaining cell is specified as the oocyte. To further understand the mechanisms that lead to proper cyst divisions , we analyzed the germ cell cycles using the Fluorescence Ubiquitin Cell Cycle Indicator (FUCCI) system. We found that cell cycle regulator activity changes dramatically upon germ cell development , presumably to prepare for the specialized cell cycles that occur upon oocyte specification. Identification of the nucleocytoplasmic transport receptor Transportin-Serine/Arginine rich as a key regulator of germ cell divisions and cell fate specification allowed us to further probe the role of cell cycle timing in the proper acquisition of fate. Together , these findings provide insight into the balance between germ cell division and fate , and identify key developmental checkpoints for proper oocyte specification.

Additional Information

Publication

Thesis

Language: English

Date: 2018

Keywords

oocyte specification, meiosis, mitosis, endocycle, FUCCI, germline stem cell, CycB, E2f1, Cul4, CRL4, cell cycle

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