All the replacement tissues with none of the ethical dilemmas?
Dividing, unfertilised eggs could offer new therapeutic option
US researchers have cloned stem cells from the unfertilized eggs of primates - our closest animal relatives. The achievement suggests it may be possible to grow cells that can give rise to any tissue in the human body without cloning and destroying human embryos.
Some researchers in the field doubt whether the technique will work in humans. And opponents of therapeutic cloning do not believe the new cells solve any of the ethical dilemmas of producing embryonic stem (ES) cells.
The dodge - called parthenogenesis - is done routinely with laboratory mice but ACT is the first to pull it off in primates. The resulting cells, called parthenotes, are clones of their mother. Experiments in mice suggest that parthenote embryos die before developing normally.
Stem-cell researchers’ ultimate goal is to replace any malfunctioning body tissue, such as diabetics faulty pancreas cells or the degrading nerve sheaths in multiple sclerosis patients. One of their greatest challenges is to get stem cells to commit to becoming a particular cell type - a process called differentiation.
Primate parthenotes are, if anything, easier to grow into different tissue types than ES cells, says West: "It’s all there: skin with hair follicles, developing eye tissue." His team even managed to create nerve cells that could produce dopamine. Human equivalents could replace the brain cells destroyed by Parkinson’s disease.
"It’s an interesting step," says Harry Griffin, of the Roslin Institute in Scotland, birthplace of Dolly the cloned sheep. But he doubts whether parthenotes will provide an alternative to therapeutic cloning - itself a long way from becoming a medical reality.
Azim Surani, a developmental biologist at Cambridge University in England agrees: Parthenote cells lack the influence of male chromosomes, which have subtle effects on cell growth and development. Although West’s cells grow in the test tube, "we cannot assume that they will behave normally when implanted in an organism," he says.
Plus stem cell therapy aims to produce cells from the patient’s own tissue that exactly match their bodies cells. And the majority of diseases that stem cells would treat are age-related. Older women no longer produce egg cells from which to make parthenote stem cells, says Griffin.
West admits that parthenotes’ potential is not fully understood. But he feels that their ready availability could be a boon to stem-cell science. "Medical researchers need to have options," he says.
Unfortunately parthenotes don’t side-step all objections to creating human embryos as a source of stem cells. "The ethical issue is not solved by this," says Bill Saunders, spokesman for the Washington DC-based Family Research Council, which opposes the use of embryos in research.
Parthenotes, although unfertilized, do form embryos, so they are living, Saunders argues. "Single-celled organisms that have the capacity to divide and grow are a member of the human species," he says.
TOM CLARKE | © Nature News Service
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences