Evolutionary origin of the cell nucleus and its functional architecture

Understanding the evolutionary origin of the nucleus and its compartmentalized architecture provides a huge but, as expected, greatly rewarding challenge in the post-genomic era We start this chapter with a survey of current hypotheses on the evolutionary origin of the cell nucleus Thereafter, we provide an overview of evolutionarily conserved features of chromatin organization and arrangements, as well as topographical aspects of DNA replication and transcription, followed by a brief introduction of current models of nuclear architecture In addition to features which may possibly apply to all eukaryotes, the evolutionary plasticity of higher-order nuclear organization is reflected by cell-type- and species-specific features, by the ability of nuclear architecture to adapt to specific environmental demands, as well as by the impact of aberrant nuclear organization on senescence and human disease We conclude this chapter with a reflection on the necessity of interdisciplinary research strategies to map epigenomes in space and time