Austrian scientists discover new mechanism for gene silencing

VIENNA, April 21 (Xinhua) -- A mechanism to close the genes has been found by Austrian scientists and their international colleagues. The mechanism is a protein, without which the so called "Methylation" from segments of the genetic material (DNA) in a plant cell cannot act.

According to a study published on the website of the scientific journal "Nature" on Wednesday, the mechanism for gene silencing was found by Marjori and Antonius Matzker from the Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austria Academy of Science, in cooperation with Max. F. Perutz Laboratories in Vienna and international colleagues.

Once the complete genetic information for the entire organism is present in every cell of the body, the cessation of DNA- segments becomes essential for the proper functioning of an organism.

Because each cell has a special function within a tissue, only specific genes work while the rest have to be kept silent. In other words, from the approximately 23,000 genes of the people in around 200 different cell types, only a small part of them is active.

So that certain genes or DNA-segments do not work, they are packed as it were. In detail, the attachment of methyl groups, the so called "methylation," takes effect. Short RNA-segments, which are molecules related to the DNA, act as an identifier that which areas are packed. It is reversible and the DNA sequence is not affected.

Viennese scientists have found only a protein in experiments, without which the packaging will not act.

RDM1, the name of proteins, can thus act as a regulator or switch. As long as RDM1 is missing, all genes in the nucleus can be read. RNA-segments of genetic material can be marked for closure primary through the protein. The scientist firstly generated random mutations in the genome of the model plant Arabidopsis thaliana and then examined the effects on a specific gene.