Genome regulation across developmental trajectories

Every cell in a worm embryo will have its DNA activity mapped, one cell at a time, from the very first division to the formation of a fully differentiated intestine. The central problem this research tackles is that we still do not understand how a single fertilised egg reliably turns into hundreds of specialised cell types, each with a unique pattern of which genes are switched on or off. Current single-cell techniques can measure gene activity in individual cells, but they cannot easily track how a mother cell’s regulatory state is inherited by its daughters. The nematode *C. elegans* solves this because its cell lineage is fixed and completely known—every cell’s family tree is identical from one worm to the next. By profiling every cell from the zygote to the 26-cell stage, and then following the 20-cell intestine through its entire development, the researchers will map how the genome wakes up after fertilisation, how cells commit to different fates, and how three-dimensional genome structure relates to gene activity. This is fundamental science with no immediate practical application, but understanding the core principles of genome regulation in a simple animal has historically revealed mechanisms—such as programmed cell death and RNA interference—that later proved universal across animals, including humans.