Comparison of Nuclear Matrix and Mitotic Chromosome Scaffold proteins in Drosophila S2 cells – Transmission of hallmarks of nuclear organization through mitosis

During open mitosis chromatin condenses to form chromosomes and decondenses post-mitotically to re-occupy their designated nuclear territory in a precisely lineage specific manner. This necessitates that features of nuclear architecture persist through mitosis. Here we present a proteomic study, which shows that the features of nuclear architecture in interphase nucleus are retained on the mitotic chromosome. Proteomic comparison was made between nuclease and high salt resistant fraction of interphase nucleus known as nuclear matrix (NuMat) and an identical biochemical fraction in the mitotic chromosome known as mitotic chromosome scaffold (MiCS). Our study elucidates that a large graction of the NuMat proteins are retained in the MiCS and possibly play an important role in maintenance of cell lineage specific features of nuclear architecture during cell division and thereby serve as components of cellular memory.