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Deep inside the cell Whether in plants or animals, cells have always fascinated scientists. Examined from every angle using ever more sophisticated research methods, cells reveal hitherto unknown gene regulatory mechanisms. Symbiosis provides inspiration for improved plant nutrition ------------------------------------------------------------------------------- Mycorrhizae result from the symbiotic association of fungi with the roots of plants. By studying this type of symbiosis more closely, researchers have discovered molecular signals synthesized by mycorrhizal fungi, called Myc factors. On the basis of tests carried out in the laboratory, they showed that these molecules, which are active in low doses, stimulate the formation of mycorrhizae not only in legumes such as alfalfa but also in species from other plant families. The scientists, who have developed Spores of a mycorrhizal fungus near a root of the host plant. bacterial genetic engineering processes for the synthesis of Myc factors, During this pre-infectious phase, the fungus releases molecular signals. are now set to test their biological activity under agricultural conditions. These natural, biodegradable molecules, which are able to promote the Unveiling the hidden face of the genome could help to improve many crop yields without using additional fertilizers.mycorrhization and growth of the root system in a wide range of plants, While carrying out large-scale sequencing of the yeast genome, geneticists have identified 1,600 new non-coding RNAs. These newly- Nature January 2011 discovered sequences, which are unusual in that they are transcribed in the opposite direction to coding RNA, can in certain circumstances regulate gene expression. This finding, which confirms that the ‘hidden face’ of genomes plays a major role in regulating gene expression, paves the way for future research into more complex organisms. New addition to the family Nature June 2011 of giant viruses After taking part in 2003 in the discovery of Mimivirus, the biggest Shedding light on the interaction virus ever found at the time, a team of researchers has come across between UVA and DNA Even bigger and genetically more complex than its close relative, this, off the coast of Chile.Megavirus chilensisa new giant virus, dubbed Ultraviolet A radiation (UVA) brings about skin cancers by causing irreversible microorganism also has seven key enzymes of the gene translation lesions in our DNA. For the first time, scientists have shown that absorption machinery, three of which are also present in Mimivirus. These of UVA radiation increases significantly when DNA is in the form of a double similarities lend support to the hypothesis that this family of giant helix. The likelihood of an absorbed UVA photon causing physical and chemical viruses shared a common ancestor that already had its own protein alteration to DNA appears to be at least ten times greater than when it is in its translation system. single strand configuration. These results need to be confirmed for nucleotide sequences as complex as natural DNA. Proceedings of the National Academy of Sciences October 2011 Journal of the American Chemical Society March 2011 12 A year at CNRS 2011


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