Abstract
When nuclei were isolated from Arabidopsis thaliana leaves in the presence of detergent, a DNA region visualized by Hoechst staining was maintained though the nuclear envelop was degraded. Isolated DNA regions were spindle-shaped, reflecting the shape of nuclei in vivo. We are examining factors involved in the maintenance of DNA regions. We asked a participation of nuclear lamina structures. A. thaliana lacking LITTLE NUCLEI 1(LINC1), one of the main lamina components, shows spherical nuclei. However, isolated demembranated nuclei of LINC1 knockout plant retained spherical DNA regions. This result suggests that LINC1 participates in the maintenance of shape of DNA region, but not in the maintenance of DNA region itself. Next, cytoskeleton inhibitor did not disperse the DNA region while α-amylase did. Assuming that possible targets of α-amylase were glycoproteins and/or carbohydrates, we treated demembranated nuclei with N-linked oligosaccharide hydrolyzing enzymes. However, the DNA region was maintained. Identification of targeted glycoproteins included in demembranated nuclei by other enzyme treatments and mass spectrometry are under investigation.
