Loss of germ cells that entered meiosis at different developmental stages was compared. Mice were injected with BrdU at 13.3, 14.3 or 15.3 days post coitum (dpc) and sacrificed either 3 days after BrdU injection or 4 days post partum (dpp). BrdU-labeled germ cells were detected in ovarian sections through double immunofluorescent staining for BrdU and either GCNA-1 or MVH as a germ cell marker. The results show that the loss of germ cells that entered meiosis at 13.3 or 15.3 dpc was excessive compared to the loss of total germ cells. Such preferential elimination was not found for germ cells that entered meiosis at 14.3 dpc. We conclude that oocyte loss during meiotic prophase is influenced by the timing of meiotic onset. / The mechanism of germ cell loss during ovarian development was tested by the presence of markers for apoptosis. Mouse ovaries were isolated at 12.5 dpc, 18.5 dpc and 2 dpp and cultured with doxorubicin (DXR) to induce cell death. Ovarian histological sections were double immunofluorescent stained for GCNA-1 and cleaved caspase-3 or PARP-1. The results suggest that caspase-3 is not activated in germ cells throughout ovarian development whereas PARP-1 is activated in germ cells at 12.5 dpc and 2 dpp but not at 18.5 dpc. Thus, no evidence has yet been provided to support the hypothesis that oocyte death during the meiotic prophase is mediated by apooptosis.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.97951 |
| Date | January 2005 |
| Creators | Fazio, Cynthia Marie. |
| 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 | © Cynthia Marie Fazio, 2005 |
| Relation | alephsysno: 002492882, proquestno: AAIMR24666, Theses scanned by UMI/ProQuest. |
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