A joint project of the Graduate School, Peabody College, and the Jean & Alexander Heard Library

Title page for ETD etd-12042008-223717


Type of Document Dissertation
Author Von Stetina, Jessica Rivera
Author's Email Address jessica.rivera@vanderbilt.edu
URN etd-12042008-223717
Title The role of alpha-endosulfine in the female meiotic cell cycle in Drosophila
Degree PhD
Department Cell and Developmental Biology
Advisory Committee
Advisor Name Title
David M. Miller Committee Chair
Keywords
  • oogenesis
  • alpha-endosufine
  • Cdc25
  • Polo
  • E3 ubiquitin ligase
  • Drosophila
  • meiosis
Date of Defense 2008-11-11
Availability unrestricted
Abstract
CELL AND DEVELOPMENTAL BIOLOGY

THE ROLE OF α-ENDOSULFINE IN THE

FEMALE MEIOTIC CELL CYCLE IN DROSOPHILA

JESSICA R. VON STETINA

Dissertation under the direction of Professor Daniela Drummond-Barbosa

Meiosis is coupled to gamete development and must be well regulated to prevent chromosomal abnormalities such as aneuploidy. During meiotic maturation, Drosophila oocytes progress from prophase I to metaphase I. The molecular factors controlling meiotic maturation timing, however, are poorly understood. My work in this thesis shows that Drosophila α-endosulfine (endos) plays a key role in this process. endos mutant oocytes have a prolonged prophase I arrest and fail to progress to metaphase I. This phenotype is similar to that of mutants of cdk1 and of twine, the meiotic homolog of cdc25, which is required for Cdk1 activation. I found that Twine and Polo kinase levels are reduced in endos mutants and identified Early girl (Elgi), a predicted E3 ubiquitin ligase, as a strong Endos-binding protein. In elgi mutant oocytes the transition into metaphase I occurs prematurely, but Polo and Twine levels are unaffected. These results suggest that Endos controls meiotic maturation by regulating Twine and Polo levels and, independently, by antagonizing Elgi. Interestingly, I also found that endos genetically interacts with Matrimony (Mtrm), which is a negative regulator of polo required to set the timing of meiotic maturation and the proper orientation of chromosomes. endos dominantly rescues the premature nuclear envelope breakdown defects observed in mtrm heterozygous females but enhances their chromosome misorientation defects, demonstrating that these processes are independent from each other. It is possible that the genetic interactions between endos and Mtrm occur via their effects on Polo, but other mechanisms are also conceivable. Finally, germline-specific expression of the human α-endosulfine ENSA rescues the endos meiotic defects and infertility, and α-endosulfine is expressed in mouse oocytes, suggesting potential conservation of its meiotic functions.

Approved: Daniela Drummond-Barbosa

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  VonStetina2008FINALthesis.pdf 10.76 Mb 00:49:48 00:25:36 00:22:24 00:11:12 00:00:57

Browse All Available ETDs by ( Author | Department )

If you have more questions or technical problems, please Contact LITS.