COLUMBUS, Ohio New research shows that a tiny piece of RNA has an essential role in ensuring that embryonic tissue segments form properly.
The study, conducted in chicken embryos, determined that this piece of RNA regulates cyclical gene activity that defines the timing of the formation of tissue segments that later become muscle and vertebrae.
Genes involved in this activity are turned on and off in an oscillating pattern that matches the formation of each tissue segment. If the timing of these genes' activity doesn't remain tightly regulated, the tissue either won't form at all or will form with defects.
One gene long associated with this segmentation "clock" is called Lfng. Researchers established in this study that a single microRNA a tiny segment of RNA that has no role in producing any protein is key to turning off Lfng at precisely the right time as tissues form in this oscillating pattern.
When the microRNA was deleted or manipulated so that it wouldn't bind when it was supposed to, the oscillatory pattern of the genetic clock was broken and tissue development was abnormal.
"It's a big deal to find that a single interaction between a microRNA and its target has this very profound effect when you interfere with its function," said Susan Cole, associate professor of molecular genetics at The Ohio State University and lead author of the study. "There are very few cases where interfering with just one microRNA during development can make this much of a difference. But here, this regulation is so tight that this turns out to be incredibly important.
"We don't think this is exclusive to chickens because the site where the microRNA binds to the RNA segment produced by Lfng is found in chickens, humans, mice and zebrafish."
A better understanding of these segmentation clocks could lead to new ways to treat certain human conditions that are traced to embryonic development. Defects in the clock are
|Contact: Susan Cole|
Ohio State University