ISSN: 2640-2637
Authors: Sulagna Mukherjee1, Sharada Iyer,Tuhina Prasadand Megha Kumar*
Recent studies show that mitosis does not involve complete eradication of the past chromatin states but the memory of active and repressed chromatin is maintained to the next generation. This epigenetic regulation is critical for embryonic development and is also required for normal physiological functions. Further, impairment in this gene regulation can result in disease conditions such as cancer. Yet, the mechanisms by which regulatory components remain bound to the compacted mitotic chromosomes is not clearly understood. Here we review the process of gene bookmarking during mitosis in the developing embryo and its impact on the transcriptional dynamics during embryogenesis. The phenomenon of bookmarking is pivotal to normal embryonic development as it ensures that the transcriptional program is faithfully inherited to maintain cell fates. We review the mechanisms which control the accessibility of regulatory regions in the genome during cell division in the developing embryo. These include regulation by transcription factors, chromatin regulators and epigenetic histone marks such as histone tail modifications. For example, the Polycomb group of genes (PcG) regulate long term memory of the repressed chromatin state in the Drosophila embryo. We will also deliberate on the latest tools and techniques available to study the phenomenon of gene bookmarking such as ATAC seq and chromosome conformation capture technique. Finally, we will also discuss some of the unanswered questions and possible future studies in this field.
Keywords: Cell Division; Embryonic Development; Chromosome; DNA
