Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers grow sperm stem cells in laboratory cultures

04.11.2004


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 http://www.nichd.nih.gov/new/releases/stem_cell.cfm.)

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 http://www.nichd.nih.gov/new/releases/green_brown_mice.cfm.)

Robert Bock | EurekAlert!
Further information:
http://www.nih.gov

More articles from Life Sciences:

nachricht Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

nachricht First transcription atlas of all wheat genes expands prospects for research and cultivation
17.08.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>