DNA recorder maps cell lineage in mouse embryos
Researchers used a DNA Typewriter system to trace how cells in a developing mouse embryo are related, starting from the first cell division and continuing through 13.5 days of development. The technique stores lineage information in the genome and allows it to be read from individual cells. The work, published in Science, could help clarify how early cell ancestry affects later development and conditions such as congenital malformations, neurodevelopmental disorders, and cancer.
The DNA Typewriter was developed by Jay Shendure and Junhong Choi. A redesigned tape was inserted into a fertilized mouse egg's genome, letting researchers read lineage records from individual cells. As cells divide, new characters are added in order without overwriting earlier ones.
The team traced relationships from the first division through 13.5 days, when organs had formed; mouse gestation lasts 19 to 21 days. Earlier efforts in a transparent roundworm succeeded, but mouse studies gave only partial pictures, and older DNA-cutting methods could leave scars.
Mapping how early cells give rise to later tissues may eventually help researchers understand congenital malformations, neurodevelopmental conditions and cancer, the authors suggest. Families affected by such conditions could benefit if lineage tracing clarifies when and where development goes awry. The approach remains experimental in mice, so any clinical relevance is likely years away, and its use in human embryos would raise practical and ethical questions that scientists and the public may need to weigh.