Following fertilization, a new life begins in the form of a single cell zygote. Initially, the zygote solely utilizes maternally provided mRNAs and proteins to support early cell divisions while maintaining parentally inherited genome transcriptionally dormant. In the absence of zygotic transcription, molecular mechanisms governing the maternal phase of developmental control are predominantly cytoplasmic and post-transcriptional. These include the regulation of maternal mRNA stability and translation. After a species-specific number of cell divisions, the zygotic phase of developmental control begins. During this time, maternal instructions are gradually degraded and replaced by zygotic RNA complement due to the transcriptional awakening of the zygotic genome. The gain of transcriptional competence of the embryo results from tightly regulated changes in chromatin organization. The emergence of newly synthesized transcripts makes the nuclear compartment a busy space as novel series of co-transcriptional RNA processing events, such as pre-mRNA splicing and pre-microRNA processing, become required.

Uncovering molecular principles underlying these gene expression dynamics is essential for understanding developmental growth and progression in animals. This collection represents a constellation of molecular and cell biology methods for studying different aspects of chromatin and RNA regulation during early embryonic development.