Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Penn Biologists Determine MicroRNA Activity Is Suppressed in Mouse Ovum

04.02.2010
Biologists at the University of Pennsylvania studying oocytes in mice, the immature egg cells necessary for sexual reproduction, have demonstrated an unusual behavior in microRNA, or miRNA, activity that may be the first event in reprogramming the differentiated oocyte into pluripotent blastomeres of the embryo. MicroRNAs are a member of the family of small RNAs, the so-called dark matter of the biological world.

MicroRNAs imperfectly pair with untranslated regions of RNA and mediate translational repression and mRNA degradation—hallmarks of the gene expression process. The Dicer enzyme, which generates small RNAs in the miRNA and RNA interference pathways, is essential for meiotic maturation of mouse oocytes.

The scientists found that the mRNA population in oocytes lacking Dicer was not enriched in miRNA binding sites, implicating a weak impact of miRNAs on regulating mRNA stability. To explore further this possibility, the scientists injected a reporter transcript, a message RNA that is not a normally present in the oocyte but contained sequences that would interact with miRNAs in the oocyte. In somatic cells, such a message would be degraded and suppressed by micro RNA. However, in oocytes, there is minimal translational repression and no degradation of the message. The finding that this pathway does not operate in oocytes is most surprising because miRNAs are implicated in controlling cell differentiation.

The data, according to researchers, presents a puzzling paradox. “Although mouse oocytes produce miRNAs, their mRNA targets are poorly repressed,” said Richard Schultz, associate dean for the natural sciences and the Charles and William L. Day Distinguished Professor of Biology in Penn’s School of Arts and Sciences. “Reducing miRNA activity during oocyte growth may have two roles. First, the low activity of miRNA-mediated mRNA degradation, perhaps linked to the absence of P bodies (structures that are implicated as sites of miRNA-mediated mRNA degradation) may contribute to mRNA stability and accumulation of mRNA in growing oocytes. Second, down-regulation of the miRNA pathway may be required for oocyte-to-zygote transition.”

The study, appearing in the journal Current Biology, was conducted by Schultz, Jun Ma and Paula Stein at Penn; Matyas Flemr, Radek Malik and Petr Svoboda of the Institute of Molecular Genetics, Academy of Sciences of the Czech Republic; and Philipp Berninger and Mihaela Zavolan of the University of Basel and Swiss Institute of Bioinformatics.

The study was funded by the National Institutes of Health, a European Molecular Biology Organization’s Strategic Development and Integration Grant and the Purkinje Fellowship.

Jordan Reese | EurekAlert!
Further information:
http://www.upenn.edu

More articles from Life Sciences:

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>