Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Engineer Mouse Embryonic Stem Cells to Form Sperm Cell Precursors

11.12.2003

For the first time, researchers using laboratory techniques alone and no animal hosts have isolated sex-cell precursors from mouse embryos, coaxed the cells into a sperm-like form, used them to fertilize mouse eggs, and ultimately formed earlystage embryos.

The research may offer a breakthrough tool for studies of embryonic cells and gene delivery, potentially helping scientists develop treatments for infertility and providing insight into the growth of certain tumors.

The researchers, led by George Daley of Children’s Hospital and the Dana Farber Cancer Institute in Boston and Niels Geijsen of Massachusetts General Hospital, also in Boston, report their findings in the December 10, 2003 Nature (online).

Researchers are excited about stem cells because they can be coaxed into forming a number of tissues, from bone to lung, while mature cells are limited to their given role.

The study builds upon nearly a decade of research at the Whitehead Institute for Biomedical Research, Harvard University, and the National Science Foundation (NSF) Biotechnology Process Engineering Center (BPEC) at the Massachusetts Institute of Technology (MIT), all in Cambridge, Mass., and most recently at Children’s Hospital Boston, the Dana Farber Cancer Institute and Massachusetts General Hospital.

Geijsen, Daley and their colleagues began their process by culturing mouse embryonic stem cells to form globular cell clusters called embryoid bodies.

In these embryoid bodies, cells differentiated into primordial germ cells (sex cell precursors), which the researchers were able to tag with a fluorescent chemical. The tag enabled the team to isolate and track the individual germ cells as the embryoid body developed.

Once the researchers had identified and isolated the germ cells, they were able to sustain continuous cell lines in a laboratory.

The researchers also found that embryoid bodies that were allowed to grow contained cells that differentiated into mature, male, sex cells similar to sperm, but they lacked tails. The team isolated those cells and injected them directly into mouse egg cells.

The eggs essentially became fertilized, and an entirely new line of early-stage mouse embryos began to grow.

In September, a team led by Toshiaki Noce of Mitsubishi Kagaku Institute of Life Sciences in Japan reported that they had derived sperm cells from embryonic stem cells. However, Gejsen, Daley and their colleagues are the first to complete the process through to the embryo stage using only laboratory techniques.

"The big difference is that our work was entirely done in vitro," says Geijsen, "whereas Noce’s group transplanted the primordial germ cells back into mouse testes to let the sperm develop."

Both approaches offer unique advantages, with the earlier study yielding mature sperm with tails, and the recent study providing the flexibility of in vitro ("in glass," or outside of an animal) experimentation that may lead to more controlled studies.

Geijsen and his colleagues also found that while many primordial germ cells formed in the laboratory environment during their study, only a few developed further into the sperm precursor cells.

"We want to understand what is missing, what we would need to make more germ cells," says Geijsen. "This understanding might have applications for treatment of male infertility," he added, for the condition can be caused by a failure of sperm to fully mature within the testicles.

The researchers also hope to use the germ cell lines to study "imprints," genetic instructions that regulate certain genes yet are missing from embryonic germ cells.

"The erasure of imprints in the primordial germ cells could have implications in cancer research," says Geijsen. "In certain tumors, imprints are erased, leading to over- expression of the imprinted gene. Since many imprinted genes have a function in controlling cell proliferation, this loss of imprinting can cause the cell to grow out of control," Geijsen added.

If the researchers can determine what causes the loss of imprints in embryonic germ cells, they can attempt to find, and counter, the mechanism that is erasing imprints in cancer cells.

The findings also contribute detailed knowledge regarding the general development of stem cells, some of the workhorses of gene therapy research and a principal target of study at NSF’s BPEC where Daley also serves as a researcher.

"Daley and his colleagues provide medical and biological expertise to BPEC, and in collaboration with other life science and engineering experts at the center, they conduct the basic research necessary for a complete understanding of stem cells," says Sohi Rastegar, the NSF program director who oversees the agency’s support of BPEC and several other bioengineering centers.

"To develop effective gene therapy for difficult diseases such as sickle cell anemia and muscular dystrophy, the use of embryonic stem cells is one of the most promising approaches and to that end fundamental knowledge of stem cells is a prerequisite," says Rastegar.

In addition to NSF, this research was also supported by the National Institutes of Health, the Dutch Cancer Society, the Leukemia and Lymphoma Society and the Harvard Society of Fellows.

Josh Chamot | National Science Foundation
Further information:
http://www.childrenshospital.org/pressroom/news.html
http://www.hms.harvard.edu/dms/bbs/fac/daleyge.html
http://www.nsf.gov

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>