The trickiest family tree in biology
family tree: The effort not only attracts developmental biologists, but geneticists and technology developers who are convinced that understanding the history of a cell – where it comes from and even what happened to it – is one of the next great frontiers of biology. The results so far provide tantalizing clues as to how humans are set in motion. The individual cells of an organ such as the brain may be more closely related to other organs than the cells of their surrounding tissue, for example. And contrary to the development of dance without the influence of C. elegans more complex organisms invoke a bit of improvisation and chance, which will certainly complicate efforts to loosen the choreography.
But even incomplete cellular ancestors could be informative in nature. Sulston cards have paved the way for discoveries around programmed cell death and small molecules of RNA regulator. The new cards could explain the role of stem cells in tissue regeneration or aid in the fight against cancer – a disease of the expansion of the non-fallow line. “There is a real sense of a new era,” says Alexander Schier, an evolutionary biologist at Harvard University in Cambridge, Massachusetts, using genome editing to trace the history of the zebrafish and other animal cell line.
Reconstruction of history
The history of a cell is written in its genome: all acquired mutations that are passed to the daughter cells used for recording. In 2005, computer scientist Ehud Shapiro at the Weizmann Institute of Science in Rehovot, Israel, has calculated that researchers could use natural mutations in individual human cells to collect their relations2. He designed a corollary (in concept at least) for the cell map of C. elegans, which he calls the human cell line project. But the camp, she said, was not ready. “When we have offered this vision, neither the scope nor the name of genomics to a single cell existed.”
A rapid advancement of a decade and the researchers developed a series of powerful tools to probe the biology of cells isolated from their RNA molecules and proteins in their individual and unique genomes. Now he is planning a way to capture the development of a human, by image, a fertilized egg from an adult. “You want the whole 3D movie with the frames from start to finish,” he said. To make such a film, you do not even need to consider the whole genome. Shapiro’s team focuses on repetitive stretches of DNA dotted around the genome known as microsatellites. These sequences tend to mutate more frequently than the other fragments of the genome, and their team is working to sequence tens of thousands of people through the genomes of hundreds of individual human cells to determine how they relate.