Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New primate stem cell

01.02.2002


All the replacement tissues with none of the ethical dilemmas?
© Science


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.



Michael West at Advanced Cell Technology (ACT) in Worcester, Massachusetts, and colleagues tricked macaque egg cells into dividing without having first been fertilized. They used a chemical cocktail similar to the one sperm use to make eggs divide.

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.

Limited application

"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.

Still controversial

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.

References

  1. Cibelli, J. B. et al. Parthenogenetic Stem Cells in Nonhuman Primates. Science, 295, 465(2002).


TOM CLARKE | © Nature News Service

More articles from Life Sciences:

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

Hope to discover sure signs of life on Mars? New research says look for the element vanadium

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>