Scientists have traced the ancestry of 1.3 million cells in a mouse embryo using a DNA recording tool, according to research published in Science on October 8. The team, led by researchers at the University of Washington in Seattle and Dartmouth College, followed development over 13.5 days.
UW Medicine said the DNA Typewriter system writes successive inherited marks into genetic material. Reading those marks reveals which cells share ancestors. This offers a way to study development inside the mother, where scientists cannot continuously watch individual cells divide, the Howard Hughes Medical Institute explained.
The team attempted recording in 100 fertilized eggs and obtained 10 embryos to examine, UW Medicine reported. Researchers concentrated on the embryo with the richest record. Nature reported that the 1.3 million edited cells represented about 10% of that embryo, so the result is not a complete census of its cells.
According to UW Medicine, the records distinguished descendants of the first two cells after fertilization. One founding cell produced more descendants, but both generated diverse cell types in almost equal proportions. Blood cells and retinal cells committed to their identities earlier than cells in the skin’s outer layer.
The institute also described independent work led by Jonathan Weissman at the Whitehead Institute, using a tool called PEtracer. Both approaches use prime editing to record cellular history. The institute said these methods can link a cell’s eventual identity with its ancestry, helping researchers examine how tissues develop.
Researchers see potential uses in studying birth defects and cancer, UW Medicine said. The institute said the data could also support artificial intelligence models of embryo development. These are research directions, not demonstrated treatments: the findings concern mice, and the detailed DNA Typewriter analysis focused on one embryo.
Comments