The role of membrane trafficking proteins during cell division in mouse oocytes.
Doctoral thesis, UCL (University College London).
Mouse oocytes undergo two successive meiotic divisions to give rise to one large functional oocyte and two small polar bodies. These divisions are crucial as anomalies in this process would preclude normal fertilization and regular development of the embryo. How this asymmetric cytokinesis is controlled is still poorly understood. The purpose of my study is to focus on the cellular events occurring during cell division (cytokinesis) in mouse oocytes, and in particular on the role of specific membrane trafficking proteins which have been found to play a role during cell division in other model organisms. My study has focused on a lipid transport protein, phosphatidylinositol transfer protein–beta (PITPβ) that can bind and transfer phosphatidylinositol and regulate the synthesis of phosphoinositides. In this study I show that PITPβ, a membrane trafficking protein which localises to the Golgi in somatic cells, does not localise to the Golgi in mouse oocytes; instead it is found in the early endosome compartment. Over-expression of PITPβ in oocytes at the germinal vesicle stage (GV) causes an abnormal accumulation of early endosomes compared to the controls. In addition, I have investigated the role of another membrane trafficking protein, the small GTP binding protein, Rab11. I have found that this protein localises strongly at the cleavage furrow of oocytes undergoing the first meiotic division. When injected with a Rab11S25N dominant-negative mutant, more than half of the oocytes remain arrested at metaphase I and do not extrude a polar body. These results suggest that Rab11 may regulate cytokinesis during the first meiotic cell division in mouse oocytes.
|Title:||The role of membrane trafficking proteins during cell division in mouse oocytes|
|Open access status:||An open access version is available from UCL Discovery|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Life Sciences > Biosciences (Division of) > Cell and Developmental Biology|
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