The sea urchin is a traditional and valuable model organism for developmental biology studies. One focus of this thesis is to study the role of septins in cell polarization in relation to the PAR6-aPKC complex in the sea urchin embryo. Immunofluorescence assays (IF) on the localization of Septin 2 in 2 and 4-cell stage embryos revealed that Septin 2 localizes to the former cell surface and is absent from the contact site between blastomeres. Further IF experiments on cytochalasin D, ML-7, and blebbistatin treated cells showed that septin is independent of the actomyosin cytoskeleton. This suggests that Septin 2 is part of a cortical memory or template that is responsible for PAR6 and GM1 localization. Another goal of this study was to annotate Septin 2 using an annotation database and web browser called Genboree at the Baylor College of Medicine annotation website. Septin 2 was successfully annotated, however further analysis is required to complete the annotation process. The third aim of this thesis was to create a cytokinesis website called the Burgess Lab Cytokinesis Resources. This is a comprehensive webpage that integrates information on the signaling, ring component, abscission proteins, and on cytokinesis in general with more emphasis on the sea urchin.
