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Updated: Jun 14, 2025
Multi-Photon Laser Ablation of Cytoplasmic Microtubule Organizing Centers in Mouse Oocytes
Published on: November 11, 2022
Phosphorylated ERM regulates meiotic maturation in mouse oocytes
Yifeng Yang1, Baozeng Xu2, Wenfa Lu3
1Jilin Provincial International Joint Research Center of Animal Breeding & Reproduction Technology, Jilin Agricultural University, Changchun, 130118, China; Key Laboratory of Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Jilin, Changchun, 130118, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, China; Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, 130112, China.
Abstract:
The cytoskeleton of mammal oocytes provides structural support to the plasma membrane and contributes to critical cellular dynamic processes such as nuclear positioning, germinal vesicle breakdown, spindle orientation, chromosome segregation, polar body extrusion, and transmembrane signaling pathways. The ERM family (ezrin, radixin and moesin) well known as membrane-cytoskeletal crosslinkers play a crucial role in organizing plasma membrane domains through their capacity to interact with transmembrane proteins and the underlying cytoskeleton. Recent works mainly focused on the structural analysis of the ERM family members and their binding partners, together with multiple functions in cell mitosis, have significantly advanced our understanding of the importance of membrane-cytoskeletal interactions. In the present study, we documented that p-ERM was expressed and localized at cortical and nucleus during mouse oocyte meiosis. p-ERM and microfilaments were colocalized from GV to MII during mouse oocyte maturation. After being treated with cytochalasin B (CB), the F-actin was disassembled. Meanwhile, p-ERM exhibited a diffuse cytoplasmic distribution and no special staining was detected in either the oocyte membrane or condensed chromosomes. p-ERM depletion by trim-away caused the meiotic procedure arrest with a significantly lower polar body extrusion rate. Collectively, these data demonstrate that the subcellular distribution of p-ERM is correlated with microfilaments. Meanwhile, the p-ERM contributes to the first polar extrusion but does not regulate the microfilament assembly.
Insights
Phospho-ERM proteins are crucial for mouse oocyte maturation and polar body extrusion. Their localization correlates with microfilaments but they do not regulate microfilament assembly.
Area of Science:
- Cell Biology
- Reproductive Biology
- Molecular Biology
Background:
- The oocyte cytoskeleton is vital for cellular dynamics and structural integrity.
- ERM proteins (ezrin, radixin, moesin) link the plasma membrane to the cytoskeleton, organizing membrane domains.
- Understanding membrane-cytoskeletal interactions is key to oocyte development.
Purpose of the Study:
- To investigate the role of phospho-ERM (p-ERM) proteins in mouse oocyte meiosis.
- To determine the localization and function of p-ERM during oocyte maturation.
- To elucidate the relationship between p-ERM and microfilaments.
Main Methods:
- Immunofluorescence microscopy to detect p-ERM and F-actin localization.
- Treatment with cytochalasin B (CB) to disrupt F-actin.
- Trim-away assay to deplete p-ERM.
- Observation of meiotic progression and polar body extrusion rates.
Main Results:
- p-ERM was expressed and localized to the cortex and nucleus during mouse oocyte meiosis.
- p-ERM colocalized with microfilaments from the germinal vesicle (GV) to metaphase II (MII) stages.
- Disruption of F-actin by CB led to diffuse p-ERM distribution.
- p-ERM depletion resulted in meiotic arrest and reduced polar body extrusion.
- p-ERM's subcellular distribution correlated with microfilaments, but it did not regulate microfilament assembly.
Conclusions:
- p-ERM localization is dependent on microfilaments during mouse oocyte maturation.
- p-ERM plays a critical role in the first polar body extrusion.
- p-ERM does not appear to regulate microfilament assembly itself.
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