Ordinary cells have the ability to replace lost organs in plants—a function previously thought to be limited to stem cells—researchers at New York University's Center for Genomics and Systems Biology and Utrecht University in the Netherlands have found.
The findings, which suggest that some roles of stem cells in organ regeneration may be shared by other types of cells, are published in the latest issue of the journal Nature.
Stem cells have two known fundamental properties: they can renew themselves and they can give rise to specialized cells. These traits make them the engines for regeneration, creating new cells to replace lost organs and tissue. These phenomena are especially evident in plants, which continually re-grow their branches and roots. The center of stem cell activity is a stem cell niche, where stem cells are directed to perform these renewal and regeneration functions.
However, it's unclear how significant the stem cell niche is to organogenesis—the building and rebuilding of organs.
The scientists studied the plant Arabidopsis thaliana. The species is a good candidate for study because researchers have previously identified all of the genes expressed in its individual cells, which allows tracking of cells' identity as they regenerate.
In the study, the researchers cut off the plant's root tip, thereby excising the stem cell niche, and examined the return of cell identities by measuring all gene activity. The results suggested that stem cells returned quite late in regeneration after other cells were already replaced. The researchers then used mutant plants in which the stem cell niche no longer functions to confirm their initial observations. Despite the absence of the stem cell niche, the plant's ordinary cells worked to regenerate all the major tissues constituting the root tip—a process that began hours after it had been removed.
However, researchers found that plants without functional stem cell niches could not resume normal growth, showing that other cells did not replace all functions of stem cells.
Scientists have recently shown that manipulating non-stem cells in mammals to express several genes could convert those cells into stem cells—a process known as reprogramming. In 2008, a Nature study conducted at the Harvard Stem Cell Institute recreated pancreatic cells in mice into another type of cell that produces insulin without the aid of stem cells. In the NYU-Utrecht study, the researchers sought to determine if entire organs regenerate in plants absent of stem cells without using genetic manipulation.
"You could think of these findings as a massive reprogramming of an organ's identity without the need for a stem cell niche," said Kenneth Birnbaum, an assistant professor of biology at NYU whose lab conducted the research. "Here is a case of an organism that can perform this kind of reprogramming naturally. This may be one reason why plants are so adept at regenerating their body parts."
The work was supported by a grant from the National Institutes of Health.
James Devitt | EurekAlert!
Ambush in a petri dish
24.11.2017 | Friedrich-Schiller-Universität Jena
Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology
High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons
The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
24.11.2017 | Physics and Astronomy
24.11.2017 | Health and Medicine
24.11.2017 | Earth Sciences