In Vitro Live Cell Imaging Reveals Nuclear Dynamics and Role of the Cytoskeleton During Asymmetric Division of Pollen Mitosis I in Nicotiana Benthamiana
Year: 2025
Type: article
Abstract: Pollen is a male gametophyte of angiosperms. Following meiosis, the microspore undergoes an asymmetric division called pollen mitosis I (PMI), which produces two cells of different sizes: a large vegetative cell and a small generative cell. Polarized nuclear migration and positioning during PMI are important for successful pollen development and cell differentiation. However, analyzing the pollen development process in real-time is challenging in many model plants with tricellular pollen, including Arabidopsis and rice. In this study, we established a method for live confocal imaging of microtubule and actin dynamics using suspension cultures with biolistic delivery of plasmid DNAs during PMI in Nicotiana benthamiana (Bentham's tobacco), containing bicellular pollen. Pharmacological studies have indicated that actin filaments are crucial for microspore nuclear positioning before PMI, cell plate expansion during cytokinesis, and chromatin dispersion in the vegetative cell nucleus after PMI. By contrast, the inhibition of microtubule assembly resulted in abnormal chromosome segregation and nuclear behavior after PMI, although nuclear positioning and asymmetric division were observed. Our in vitro live cell imaging system for PMI provides insights into the importance of cytoskeletal regulation in asymmetric division and differentiation during pollen development.
Source: Cytoskeleton
DOI: 10.1002/cm.70003
Authors: Yoko Mizuta, Masako Igarashi, Tomomi Shinagawa, Ikuma Kaneshiro, Haoto Anan, Daisuke Kurihara
Language: English
Topic: Plant Reproductive Biology
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,920
OpenAlex ID: W4411577328