Keeping this involved process on the straight and narrow requires a clever balance of promotion and inhibition, said researchers from Baylor College of Medicine in Houston in a report that appears in the current edition of the journal Developmental Cell.
"Our finding should have implications for the entire stem cell field," said Dr. Soo-Kyung Lee, assistant professor of molecular and cellular biology at BCM. "Scientists are seeking to make particular cell types using combinations of embryonic genes. They need to keeping mind that you do not just push them forward down one pathway. You must also suppress related pathways."
"During embryonic development, one needs to generate a lot of different types of neurons," said Lee, also a faculty member in the BCM Graduate School of Biomedical Sciences. "How are they being generated at the right time and place? To assemble the brain, you need all these different types of neurons. With a limited number of genes, how do you generate such a complex system?"
"We want to understand the molecular mechanisms that allow one gene to influence the formation of many neurons," she said.
They found that both promotion of one pathway and inhibition of another are required to keep the cells on the right road to cell fate determination.
"One factor does not determine cell fate," she said. It's a combination of factors or genes that together affect neuron formation.
She and her colleagues concentrated their work on the development of motor neurons in mice. Two types of nerve cells – spinal motor neurons and V2-interneurons – are required for motor coordination. As they become those cells, they share important regulatory factors, said Lee.
"They share a cell lineage pathway," she said. "We asked how do we generate two different lineages from one pathway?"
A cocktail of the transcription factors Isl1 and Lhx3 can cause embryonic cells to become motor neurons, she said.
"If we put only Lhx3 into the embryonic neural stem cells, they become V2-interneurons," she said. However, deleting the genes can cause the pathways to converge, resulting in hybrid cells that result in the death of the embryos.
This does not happen in Nature, she said, and they found that a gene called Hb9, expressed only in motor neurons, blocks the ability of Lhx3 to cause embryonic neural stem cells to become the V2-interneurons.
"Once you turn on the complex of Isl1 and Lhx3, then you also turn on a repressor that blocks the cells from going down the alternative pathway to becoming V2-interneurons," she said. The motor neuron fate of those cells is sealed. They found a similar repressor function in the V2-interneuron pathway.
"We think this is a delicately developed system," said Lee. "We don't think this mechanism is restricted to motor neurons."
Bacteria as pacemaker for the intestine
22.11.2017 | Christian-Albrechts-Universität zu Kiel
Researchers identify how bacterium survives in oxygen-poor environments
22.11.2017 | Columbia University
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...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Business and Finance
22.11.2017 | Physics and Astronomy
22.11.2017 | Physics and Astronomy