Epigenetic regulation of cis-regulatory elements and transcription factors during development

Epigenetic mechanisms help the chromatin organize and regulate complex genomes by governing access to the cellular machinery and fine-tuning gene expression. Genome regulation occurs mainly by controlling the level of transcription via cis-elements, DNA sequences interspersed within and around coding genes, and the trans-factors that recognize and bind to them. Cellular memory operates via the epigenetic interaction of these elements to provide the genome with the ability to store regulatory information that governs all biological processes, including development. Gametogenesis and embryogenesis involve large-scale genome reprogramming to enable embryonic growth and development, cell fate and lineage commitment, and tissue differentiation to make a functional organism. This chapter discusses how early development is initiated and proceeds along epigenetically governed pathways and the cis-regulatory elements and trans-acting factors that control them.