Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study of planarians offers insight into germ cell development

24.04.2007
The planarian is not as well known as other, more widely used subjects of scientific study - model creatures such as the fruit fly, nematode or mouse. But University of Illinois cell and developmental biology professor Phillip Newmark thinks it should be.

As it turns out, the tiny, seemingly cross-eyed flatworm is an ideal subject for the study of germ cells, precursors of eggs and sperm in all sexually reproducing species.

The planarian Newmark studies, Schmidtea mediterranea, is a tiny creature with a lot of interesting traits. Cut it in two (lengthwise or crosswise) and each piece will regenerate a new planarian, complete with brains, guts and - in most cases - gonads. Even when the planarian's brain is severed from its body, it can regenerate all that is removed, including the reproductive organs.

In a new study published this month in the Proceedings of the National Academy of Sciences, Newmark and his colleagues at the U. of I. report that planarians share some important characteristics with mammals that may help scientists tease out the mechanisms by which germ cells are formed and maintained. Newmark's team made a few discoveries related to a gene, called nanos, which was previously known to play a critical role in germ cell development in several other model organisms.

... more about:
»Newmark »germ cells »inductive »nanos »planarian

Unlike fruit flies and nematodes, which show signs of germ cell initiation in the earliest stages of their embryonic development, planarians do not generally express nanos or produce germ cells until several days after hatching. This delayed initiation of germ cell growth is called inductive specification, and is common to mammals and a number of other animals.

Graduate student Yuying Wang and the other team members were able to show that nanos is essential for inductive specification in planarians. Blocking nanos expression by means of RNA interference immediately after the planarians hatched prevented the emergence and development of germ cells. Blocking nanos in mature adults caused their ovaries and testes to disappear. And when the researchers blocked nanos expression in planarians that had had their bodies and reproductive organs detached from their brains, the planarians regenerated new bodies, but with no reproductive cells.

"This is the first time that nanos gene function has been studied in a non-traditional model organism," Newmark said. "This is important because planarians, like mammals, seem to make their germ cells by an inductive mechanism. So we're hoping that we can use the molecular biological tools available for studying planarians to get at the mechanisms that tell a cell: 'You're going to be a germ cell.' "

S. mediterranea also has the ability to reproduce asexually: It clones itself by means of fission. In looking at nanos in asexual individuals of this species, the researchers made the surprising discovery that these asexual individuals also express nanos and produce germ cells. Some other mechanism, as yet unknown, prevents these germ cells from developing into functional testes and ovaries.

"Having a simple organism that also uses inductive signaling is going to help us tease apart the more conserved mechanisms (of germ cell development and maintenance)," Newmark said. "We hope that this information will also prove informative for understanding these processes in higher organisms."

Editor's note: To reach Phillip Newmark, call 217-244-4674; e-mail:
pnewmark@uiuc.edu.

Diana Yates | University of Illinois
Further information:
http://www.news.uiuc.edu/news/07/0423germcells.html

Further reports about: Newmark germ cells inductive nanos planarian

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>