Navigation Links
Penn biologists determine microRNA activity is suppressed in mouse ovum
Date:2/3/2010

PHILADELPHIA - 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 degradationhallmarks 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."


'/>"/>

Contact: Jordan Reese
jreese@upenn.edu
215-573-6604
University of Pennsylvania
Source:Eurekalert

Related biology news :

1. CCNY biologists identify new spiny pocket mouse species
2. Penn biologists explain how organisms can tolerate mutations, yet adapt to environmental change
3. Biologists merge methods, results from different disciplines to find new meaning in old data
4. New handbook for biologists who need more competence or confidence in statistics
5. Biologists discover bacterial defense mechanism against aggressive oxygen
6. Beyond genomics, biologists and engineers decode the next frontier
7. Biologists, educators recognize excellence in evolution education
8. NIMBioS hosts tutorial on optimal control and optimization for biologists
9. Biologists discover death stench is a universal ancient warning signal
10. UTSA plant biologists publish where their peers are -- on the Web
11. Microbiologists find defense molecule that senses respiratory viruses
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/15/2016)... , April 15, 2016  A new partnership ... more accurate underwriting decisions in a fraction of ... competitively priced and high-value life insurance policies to ... With Force Diagnostics, rapid testing (A1C, ... data readings (blood pressure, weight, pulse, BMI, and ...
(Date:4/13/2016)... CHICAGO , April 13, 2016  IMPOWER physicians ... are setting a new clinical standard in telehealth ... By leveraging the higi platform, IMPOWER patients can ... weight, pulse and body mass index, and, when they ... quick and convenient visit to a local retail location ...
(Date:3/29/2016)... , March 29, 2016 ... "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are pleased to ... ink used in a variety of writing instruments, ensuring ... of originally created collectibles from athletes on LegacyXChange will ... analysis of the DNA. Bill Bollander ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... ... June 24, 2016 , ... Researchers at the Universita ... miRNAs in people with peritoneal or pleural mesothelioma. Their findings are the subject of ... now. , Diagnostic biomarkers are signposts in the blood, lung fluid or tissue ...
(Date:6/23/2016)... 23, 2016   Boston Biomedical , an ... designed to target cancer stemness pathways, announced that ... Orphan Drug Designation from the U.S. Food and ... cancer, including gastroesophageal junction (GEJ) cancer. Napabucasin is ... inhibit cancer stemness pathways by targeting STAT3, and ...
(Date:6/23/2016)... 23, 2016 Houston Methodist Willowbrook Hospital ... Sports Association to serve as their official health ... Methodist Willowbrook will provide sponsorship support, athletic training ... association coaches, volunteers, athletes and families. ... Sports Association and to bring Houston Methodist quality ...
(Date:6/23/2016)... -- The Biodesign Challenge (BDC), a university competition that asks ... systems and biotechnology, announced its winning teams at the ... York City . The teams, chosen ... MoMA,s Celeste Bartos Theater during the daylong summit. Keynote ... of architecture and design, and Suzanne Lee , ...
Breaking Biology Technology: