Unicellular microRNA discoveryApril 30, 2007In the May 15th issue of Genes & Development, an international collaboration of researchers, led by Dr. Yijun Qi (National Institute of Biological Sciences, China), report on their discovery of microRNAs in the unicellular green alga, Chlamydomonas reinhardtii. This is the first finding of microRNAs in a unicellular organism. "The finding changes the dogma that miRNAs only exist in multicellular organisms, and adds an important piece into the blooming small RNA world. A pressing question we have now is what these miRNAs are exactly doing in the green alga. I hope we will know the answers soon," says Dr. Qi. MicroRNAs (miRNAs) are a class of conserved, approximately 21-nucleotide long RNAs that regulate the expression of genes by either cleaving complementary mRNA targets or repressing their translation. MiRNAs have been identified in both plants and animals, acting as key regulators of multicellular development. Dr. Qi and colleagues now extend the range of miRNAs into unicellular organisms, with their discovery of a large number of miRNAs in green algae. The researchers showed that unicellular miRNAs share functional characteristics with plants miRNAs, in so far as they can direct the cleavage of target mRNAs in vitro and in vivo. Furthermore, they found that miRNA expression patterns changed during gamete differentiation, suggesting a possible role in regulating sexual reproduction. The discovery of miRNAs in a unicellular organism has evolutionary implications as well. While the existence of miRNAs in unicellular and multicellular organisms suggests that the miRNA pathway arose before these lineages split, the lack of universally conserved miRNA genes in algae, plants and animals suggests that they may have evolved independently. Cold Spring Harbor Laboratory |
|||||||||||||||||||||
| Related MiRNAs Current Events and MiRNAs News Articles Lung cancer suppresses miR-200 to invade and spread Primary lung cancer shifts to metastatic disease by suppressing a family of small molecules that normally locks the tumor in a noninvasive state, researchers at The University of Texas M. D. Anderson Cancer Center report in the Sept. 15 edition of Genes and Development. MicroRNAs circulating in blood show promise as biomarkers to detect pancreatic cancer A blood test for small molecules abnormally expressed in pancreatic cancer may be a promising route to early detection of the disease. Predicting cancer prognosis Researchers led by Dr. Soheil Dadras at the Stanford University Medical Center have developed a novel methodology to extract microRNAs from cancer tissues. International research team seeks to unravel flatworm regeneration Planarian flatworms are only a few millimeters up to a few centimeters in length, live in freshwater and are the object of intense research, because they possess the extraordinary ability to regenerate lost tissue with the help of their stem cells (neoblasts) and even grow an entirely new worm out of minute amputated body parts. Study in Nature: MicroRNAs hold promise for treating diseases in blood vessels A newly discovered mechanism controls whether muscle cells in blood vessels hasten the development of both atherosclerosis and Alzheimer's disease, according to an article published online today in the journal Nature. Gladstone scientists identify genetic factors that hold promise for treatment of vascular diseases Researchers at the Gladstone Institute of Cardiovascular Disease (GICD) have discovered a key switch that makes stem cells turn into the type of muscle cells that reside in the wall of blood vessels. MicroRNAs help control HIV life cycle Scientists at Burnham Institute for Medical Research (Burnham) have discovered that specific microRNAs (non-coding RNAs that interfere with gene expression) reduce HIV replication and infectivity in human T-cells. Research uncovers clues to virus-cancer link In a series of recently-published articles, a research team from the University of North Carolina at Chapel Hill Lineberger Comprehensive Cancer Center has uncovered clues to the development of cancers in AIDS patients. Sequencing the cow's genetic code -- a new agricultural era dawns Researchers from the Universities of Geneva and Lausanne, as well as the Swiss Institute of Bioinformatics have been part of a major international project to sequence the bovine (cow) genome, a female Hereford cow named L1 Dominette. Genetic variations in miRNA processing pathway and binding sites help predict ovarian cancer risk Genetic variations in the micro-RNA (miRNA) processing pathway genes and miRNA binding sites predict a woman's risk for developing ovarian cancer and her prospects for survival. More MiRNAs Current Events and MiRNAs News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||