This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: For decades, scientists have been able to look at individual moments in the development of an embryo: a snapshot of a developing brain, a picture of how the heart takes shape or a glimpse of cells beginning to form the nervous system. But what if instead of taking snapshots, they could watch the entire process unfold?
A new study out of the lab of Whitehead Institute member Jonathan Weissman, also a professor of biology at the Massachusetts Institute of Technology (MIT) and a Howard Hughes Medical Institute (HHMI) investigator, offers one of the most detailed views yet of how a mammal is built, cell by cell. By following the family history of over a million cells as a mouse embryo develops, the researchers have created a kind of developmental blueprint, or movie, showing how cells divide and ultimately become the tissues and organs in the body. This work, published Oct. 8 in the journal Cell and conducted in collaboration with Zachary Smith's group at Yale University and the Max Planck Institute for Molecular Genetics, provides a comprehensive view of a process that has long been studied in pieces: how a single fertilized egg gives rise to hundreds of different kinds of cells, arranged in the right places and at the right times to build an animal.
"This is really a view of how the information in the genome plays out over space and time to go from linear DNA to a three-dimensional animal," Weissman says. The map could have broad implications for understanding birth defects and cancer. Many birth defects arise when cells change course as tissues and organs are being assembled.
A detailed map of typical development could help researchers pinpoint where and when those processes go awry. In cancer, the same approach could help scientists trace when cells acquire traits such as the ability to spread or resist treatment. The map could also inform stem cell research by revealing the sequence of cell states that leads to mature, functional cell types.
In the 1980s, scientists ventured into similar territory by painstakingly following the development of Caenorhabditis elegans, a tiny worm whose transparent body contains only about 1,000 cells. Using microscopy, they could trace how individual cells divided and where their descendants ended up. But achieving something similar in a mammal was a challenge on a vastly different scale.
Mammalian embryos contain far more cells, develop inside the uterus—out of sight—and do not follow a completely predetermined script. The new study tackles this challenge using a technology developed in the Weissman Lab called PEtracer. The system acts somewhat like a flight recorder inside a cell.
Extract — continue reading at the source.
