Roles of focal adhesion, phosphoinositide lipids and cytoskeleton in Caenorhabditis elegans ovulation.

Xu, Xiaojian.

Roles of focal adhesion, phosphoinositide lipids and cytoskeleton in Caenorhabditis elegans ovulation.

dc.contributor.advisor	Lee, Myeongwoo.
dc.contributor.author	Xu, Xiaojian.
dc.contributor.department	Biology.
dc.contributor.other	Baylor University. Dept. of Biology.	en
dc.date.accessioned	2007-02-19T16:52:33Z
dc.date.available	2007-02-19T16:52:33Z
dc.date.copyright	2007
dc.date.issued	2007-02-19T16:52:33Z
dc.description	Includes bibliographical references (p. 92-102)
dc.description.abstract	Ovulation provides us with a robust in vivo model to study how the gonad contracts and releases eggs. By dissecting different molecules and signaling pathways in the process of gonad contraction, I have gained insights on how focal adhesion, phosphoinositide lipids, and cytoskeleton coordinate ovulation, a rhythmic behavior of C. elegans. Integrin plays an essential role in ovulation via the phosphoinositide signaling pathway. My studies have determined that ovulation defects caused by RNAi of pat-3/ [beta] integrin or ECM molecules is suppressed by increased IP3 signaling, demonstrating that cell-ECM interaction is essential for ovulation, which is mediated via IP3 signaling. Additional studies have demonstrated that loss of other focal adhesion molecules, pat-4/ILK and unc-112/Mig-2 causes defects in gonad sheath contraction and spermatheca dilation and disrupts gonad cytoskeleton. I have also identified one more IP3 signaling gene involved in C. elegans ovulation, which is phosphatidylinositol-4-phosphate 5' kinase (ppk-1/PIP5K). ppk-1 is mainly expressed in the somatic gonad. Depletion of PPK-1 results in sterility and impairs gonad sheath contractility. Further analysis reveals that ppk-1 RNAi induced sterility can be suppressed by increased IP3 signaling and that ppk-1 is also linked to unc-54/myosin B, demonstrating that ppk-1 plays an important role in IP3 signaling and organizes cytoskeleton in somatic gonad. Taken together, these studies enable me to conclude that ovulation is a rhythmic cellular behavior that requires coordination of signaling paths: focal adhesion, phosphoinositide lipids and cytoskeleton proteins to induce timely release of a matured egg from the ovary to the spermatheca for fertilization.	en
dc.description.degree	Ph.D.
dc.description.statementofresponsibility	by Xiaojian Xu.
dc.format.extent	5646184 bytes
dc.format.extent	4448371 bytes
dc.format.extent	7564099 bytes
dc.format.extent	8151611 bytes
dc.format.extent	4008421 bytes
dc.format.extent	7087627 bytes
dc.format.extent	6483694 bytes
dc.format.extent	x, 102 p. : ill.	en
dc.format.mimetype	application/octet-stream
dc.format.mimetype	application/octet-stream
dc.format.mimetype	application/octet-stream
dc.format.mimetype	application/octet-stream
dc.format.mimetype	application/octet-stream
dc.format.mimetype	application/octet-stream
dc.format.mimetype	application/octet-stream
dc.identifier.citation	Xu X, Lee D, Shih HY, Seo S, Ahn J, Lee M. 2005. Linking integrin to IP(3) signaling is important for ovulation in Caenorhabditis elegans. FEBS Lett. 579(2):549-53.
dc.identifier.citation	Xu X, Rongali SC, Miles JP, Lee KD, Lee M. 2006. pat-4/ILK and unc-112/Mig-2 are required for gonad function in Caenorhabditis elegans. Exp Cell Res 312(9):1475-83.
dc.identifier.uri	http://hdl.handle.net/2104/4904
dc.language.iso	en_US	en
dc.rights	Baylor University theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact librarywebmaster@baylor.edu for inquiries about permission.	en
dc.rights.accessrights	Baylor University access only	en
dc.subject.lcsh	Caenorhabditis elegans.
dc.subject.lcsh	Ovulation.
dc.title	Roles of focal adhesion, phosphoinositide lipids and cytoskeleton in Caenorhabditis elegans ovulation.	en
dc.type	Thesis