Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers grow sperm stem cells in laboratory cultures


Advance could lead to new infertility treatments, source of adult stem cells

Spermatogonial stem cells expressing green fluorescent protein.

A team of researchers working with cells from mice has overcome a technical barrier and succeeded in growing sperm progenitor cells in laboratory culture. The researchers transplanted the cells into infertile mice, which were then able to produce sperm and father offspring that were genetically related to the donor mice. "This advance opens up an exciting range of possibilities for future research, from developing new treatments for male infertility to enhancing the survival of endangered species," said Duane Alexander, M.D., Director of the NICHD. Their research, funded in part by the National Institute of Child Health and Human Development of the National Institutes of Health, will be published online this week in an upcoming issue of Proceedings of the National Academy of Sciences.

Led by Hiroshi Kubota, D.V.M., Ph.D., the team of researchers from the University of Pennsylvania School of Veterinary Medicine in Philadelphia, also included Mary Avarbock and Ralph L. Brinster V.M.D., Ph.D. The researchers succeeded in developing the culture medium containing the precise combination of cellular growth factors needed for the cells to reproduce themselves outside the body. Known as spermatogonial stem cells, the cells are incapable of fertilizing egg cells but give rise to cells that develop into sperm.

In 1994, this same research team developed the means to transplant spermatogonial stem cells from one mouse into another. The recipient mice then produced sperm--fully capable of fertilizing egg cells--with the genetic characteristics of the donor mice. Because they can now grow spermatogonial stem cells in culture, researchers have a ready source of cells that they could manipulate genetically, explained the study’s senior author, Ralph Brinster.

For example, researchers could implant a new gene into a spermatogonial cell, reproduce a large number of spermatogonial cells in the culture medium, and then implant the cells into recipient animals. These animals could then pass the new trait on to their offspring. The ability to introduce a new trait into animals would greatly assist breeders of both livestock and laboratory animals. Moreover, by culturing and freezing spermatogonial stem cells from a valuable livestock animal or an endangered species, researchers could extend the reproductive life of that animal indefinitely. (The researchers developed a technique for successfully freezing and thawing spermatogonial cells in 1996.)

By manipulating the culture media that contains the spermatogonial stem cells, researchers might also be able to induce the spermatogonial cells to develop into sperm cells that could be used to fertilize eggs, providing a method to treat some types of infertility. "This finding is likely to be applicable to humans," Dr. Brinster said. He added that the same growth factors needed to culture the mouse stem cells would likely foster the growth of human spermatogonial cells as well as the cells of other mammals.

Currently, males who undergo chemotherapy that renders them infertile can store their semen so that it can be used at a later date, should they wish to father children. However, this approach results in a less than 50 percent success rate. Boys who are too young to provide a semen sample but who also need such chemotherapy treatments could also be helped by the new technique. Their spermatogonial stem cells could be cultured to increase their numbers, frozen, and reimplanted at a later date, restoring their fertility.

Moreover, the new culture technique would allow researchers to further investigate the potential of spermatogonial stem cells as a source for more versatile adult stem cells to replace diseased or injured tissue. The replacement tissue might be used to help patients with spinal cord injury, or disorders like Parkinson’s disease or heart disease.

To conduct their study, Dr. Kubota and his colleagues began with mice that had been genetically altered to express green fluorescent protein, or GFP, which gives off a green light in the presence of a certain wavelength of light. During key stages of the experiment, tissue from the donor mice gave off a green light.

At the first step, the researchers could distinguish spermatogonial stem cells from the cells used to nurture them in lab cultures by the green light the spermatogonial stem cells gave off. (A photograph of the spermatogonial stem cells appears at

The spermatogonial stem cells also gave off green light when they grew and reproduced in the testes of the recipient mice. Similarly, about half of the baby mice fathered by the recipient mice also glowed green (See photo at

Robert Bock | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>