Mosses may provide new “compass” for stem cell research

WASHINGTON - Mosses can now act as a novel “compass” for scientists to better program stem cells for medical purposes, according to Israeli and German scientists.

Dr. Nir Ohad of Tel Aviv University’s Department of Plant Sciences and Prof. Ralf Reski of the University of Freiburg have discovered a new use for the Polycomb group proteins (PcG) found in moss.

They believe that the PcG proteins play an important role in telling stem cells how to develop.

Moss is a kind of plant that shares basic development processes with those found in humans.

“We may not have found the switch that turns stem cells into tissue, but we have found a key component which makes this switch work,” said Ohad.

In their study, researchers described an ancient mechanism that alters the way DNA organizes inside the cell nucleus, which in turn, affects gene expression.

The finding has important implications in stem cell therapies, which can go awry if implanted stem cells are not reprogrammed properly.

The researchers examined the “central regulatory function” of the PcG complex and how it programs an organism’s development, including the first divisions of cells as a new organism is born.

Insights from this research have implications for plant and human development alike, and could be applied to cancer research with time.

“As far as we know, there are some instances in cancer where the cellular mechanisms are defective or impaired. When this happens, it can lead to the misregulation of the genetic code, which can then lead to the breakdown of a healthy cell,” said Ohad.

He added that this “switch,” which ensures the proper development of the organism, emerged early in the evolution of all organisms with a nucleus and organized DNA, long before animals and plants evolved into vastly different species and genera.

The researchers suggest that the basic function of the PcG mechanism in moss, common to its function in plants and humans, is in regulating cell differentiation, describing the point at which a stem cell “decides” to become a leaf or flower, for example.

The findings of the study provide science a tool to control tissue specification, timing of reproduction and the development of traits in seeds that serve as the source for human and animal feed.

The study has been published in the journal Development. (ANI)