Lipid Mapping of Cell Mitosis by Non-covalent Migratory Fluorescence Labelling

Description

Abstract

The concept of non-covalent migratory fluorescence labelling is introduced to spatially and temporally map intracellular lipids throughout a cycle of cell division. This hands-off approach utilizes a small molecule BF₂-azadipyrromethene fluorophore, NM-ER, to first label the nuclear membrane and endoplasmic reticulum of cells at interphase but which can migrate with the lipid components of these structures throughout mitosis as they disassemble, redistribute and reassemble prior to daughter cell separation. Through this unique approach to image capture, key prometaphase events such as lipid intrusion into the nuclear body and nuclear membrane disassembly are observable, as are the stages of nuclear membrane reassembly in telophase and lipid distributions during cytokinesis. When used alone NM-ER can distinguish each phase of cell mitosis from lipid staining patterns, is compatible with STED super resolution imaging, and with an emission max of 648 nm makes it useable with other common GFP and nuclear DNA stains. The non-covalent NM-ER label remains associated with the originating lipid components as they undergo the architectural reorganizations and changes of subcellular localization associated with mitosis. As lipid-based structures are influenced by numerous biological processes and mechanical forces, such a fluorescence imaging tool could broadly offer novel perspectives on lipid behavior in live cells.