Cell cycle checkpoints are signal transduction pathways that control the order and timing of cell cycle transitions, ensuring that critical events are completed before the cell cycle proceeds. The Chk2 family of kinases plays a central role in mediating responses to DNA damage or DNA replication blocks in various organisms. My functional analysis of the Drosophila serine/threonine kinase Loki/Chk2 shows that fly chk2 monitors double-strand breaks caused by irradiation during S and G2 phases and induces cell cycle arrest in embryonic cells around cellularization. / loki is also required for the normal number of germ line cells to form in the embryo, and for normal modification of Vasa, a crucial factor in germ cell formation. However, during normal oogenesis loki expression is suppressed by orb. Another group described the involvement of Drosophila loki/chk2 in the meiotic pachytene checkpoint. Using our loki·null mutant, I obtained the opposite result: loki/chk2 does not have an essential function in this process. / The second part of my thesis deals with the question of how cells are instructed about their identity in a developing organism. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.80329 |
| Date | January 2003 |
| Creators | Masrouha, Nisrine |
| Contributors | Suter, Beat (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002090197, proquestno: AAIMQ98698, Theses scanned by UMI/ProQuest. |
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