COLUMBUS, Ohio A new way to visualize single-cell activity in living zebrafish embryos has allowed scientists to clarify how cells line up in the right place at the right time to receive signals about the next phase of their life.
Scientists developed the imaging tool in single living cells by fusing a protein defining the cells' cyclical behavior to a yellow fluorescent protein that allows for visualization. Zebrafish embryos are already transparent, but with this closer microscopic look at the earliest stages of life, the researchers have answered two long-standing questions about how cells cooperate to form embryonic segments that later become muscle and vertebrae.
Though these scientists are looking at the molecular "clock" that defines the timing of embryonic segmentation, the findings increase understanding of cyclical behaviors in all types of cells at many developmental stages including problem cells that cause cancer and other diseases. Understanding how to manipulate these clocks or the signals that control them could lead to new ways to treat certain human conditions, researchers say.
Embryonic cells go through oscillating cycles of high and low signal reception in the process of making segmented tissue, and gene activation by the groups of cells must remain synchronized for the segments to form properly. One of a handful of powerful messaging systems in all vertebrates is called the Notch signaling pathway, and its precise role in this oscillation and synchronization has been a mystery until now.
In this study, the researchers confirmed that the cells must receive the Notch signal to maintain synchronization with nearby cells and form segments that will become tissue, but the cells can activate their genes in oscillating patterns with or without the signal.
"For the first time, this nails it," said Sharon Amacher, professor of molecular genetics at Ohio State University and lead author of the study.
|Contact: Sharon Amacher|
Ohio State University