TILLING (molecular biology)

TILLING, abbreviated for engl. Targeting Induced Local Lesions in Genomes ( targeted induced local lesions in genomes ), is a molecular biological method, with the help of point mutations in a particular gene can be identified specifically. The method combines a standard technique, the mutagenesis using ethyl methanesulfonate (EMS ), with a new screening method based on the detection of mismatch hybridization by HPLC. It was cut with a restriction enzyme, Cell, the double stranded DNA at the mismatch sites optimized.

The method was introduced in 2000 for the Arabidopsis genome and has since been applied to other organisms.

Traditional mutagenesis screens as the EMS mutagenesis can put point mutations, the identification of point mutations in the gene to be mutagenized is very time consuming.

The TILLING technology allows testing of many potential mutants simultaneously in a high throughput. However, it can only be found mutations in a known piece of DNA were prepared for the already specific primers.

An additional application is to find SNPs that are later integrated into appropriate databases.

The TILLING is cited as an alternative to agricultural biotechnology, as hereby without in foreign genes results can be obtained which are close to some results from genetic engineering. For example, a potato was produced in which the gene is inactivated, which produces undesirable amylose starch. A product of plant genetic engineering with comparable properties is Amflora. Since the species boundaries in TILLING is not exceeded, this method is acceptable for organizations like Greenpeace, who reject the Green genetic engineering. Innovative features such as insect resistance Bt toxins are not possible.

The treatment of the plants with mutagenic chemicals in TILLING generates a large number of point mutations. Therefore, not only the desired features to be found, the plants lose some useful properties that are back-crossed by many years of breeding with high-yielding varieties. In the case of Amflora alternative, this took six years. In the EU can be brought to market generated by TILLING as conventionally bred plants, in Canada they must go through an approval process, such as genetically modified varieties.