CHARACTERISATION OF A NOVEL SPINDLE DOMAIN IN MAMMALIAN MEIOSIS
type: CreativeWork
description: The organisation of microtubule networks into a bipolar spindle is essential for reliable chromosome segregation during cell division. A pair of centrioles surrounded by pericentriolar material (PCM), define the canonical centrosome that acts as the main microtubule organising centre (MTOC) during mitosis. In mammalian meiosis, centrioles are eliminated early on during oogenesis. Despite the absence of centrosomes, a large number of centrosomal proteins are highly expressed in mouse oocytes. Here, I characterise the localisation and function of centrosomal proteins at a previously undescribed meiotic spindle pole domain (MSPD). An initial protein screen identified a group of pericentriolar satellite proteins that localised to a previously undescribed spindle pole domain throughout meiotic maturation in mouse oocytes, including Pericentriolar material 1 protein (PCM1). This domain was distinct from spindle microtubules and the acentrosomal microtubule organising centres (aMTOCs). Initial characterisation focused on PCM1, the main centriolar satellite scaffold protein in somatic cells. Depletion of PCM1 revealed interdependence with the essential aMTOC component, Pericentrin. In the absence of PCM1, aMTOCs could no longer assemble or maintain their structural integrity. PCM1 degradation and disassembly of aMTOCs disrupted spindle assembly and reduced the total amount of nucleated microtubules throughout meiosis. In the absence of the main microtubule nucleating aMTOCs, oocytes relied on the Ran GTPase activity to form a small bipolar spindle. A similar mechanism was previously reported in human oocytes that lack prominent MTOCs. The extended centrosomal protein screen identified additional components of the MSPD. TACC3, under the regulation of Aurora-A at aMTOCs, drive assembly of the MSPD. This domain was absent in MTOC free human oocytes but a second population of TACC3 (identified in mouse oocytes) localised to the meiotic spindle and K-fibres was essential for mai…
abstract: The organisation of microtubule networks into a bipolar spindle is essential for reliable chromosome segregation during cell division. A pair of centrioles surrounded by pericentriolar material (PCM), define the canonical centrosome that acts as the main microtubule organising centre (MTOC) during mitosis. In mammalian meiosis, centrioles are eliminated early on during oogenesis. Despite the absence of centrosomes, a large number of centrosomal proteins are highly expressed in mouse oocytes. Here, I characterise the localisation and function of centrosomal proteins at a previously undescribed meiotic spindle pole domain (MSPD). An initial protein screen identified a group of pericentriolar satellite proteins that localised to a previously undescribed spindle pole domain throughout meiotic maturation in mouse oocytes, including Pericentriolar material 1 protein (PCM1). This domain was distinct from spindle microtubules and the acentrosomal microtubule organising centres (aMTOCs). Initial characterisation focused on PCM1, the main centriolar satellite scaffold protein in somatic cells. Depletion of PCM1 revealed interdependence with the essential aMTOC component, Pericentrin. In the absence of PCM1, aMTOCs could no longer assemble or maintain their structural integrity. PCM1 degradation and disassembly of aMTOCs disrupted spindle assembly and reduced the total amount of nucleated microtubules throughout meiosis. In the absence of the main microtubule nucleating aMTOCs, oocytes relied on the Ran GTPase activity to form a small bipolar spindle. A similar mechanism was previously reported in human oocytes that lack prominent MTOCs. The extended centrosomal protein screen identified additional components of the MSPD. TACC3, under the regulation of Aurora-A at aMTOCs, drive assembly of the MSPD. This domain was absent in MTOC free human oocytes but a second population of TACC3 (identified in mouse oocytes) localised to the meiotic spindle and K-fibres was essential for mai…
author: Seres, Karmen Bianka
language: en
keywords: Meiosis, PCM1, aMTOCs, Spindle, centrosomes, Lightsheet, TACC3, oocyte
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/2763507f-9bfe-4b3f-98a5-19cc1935f892/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2019-05-18
date modified: 2026-07-22T22:24:27Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.35676