TILLING
TILLING , abbreviated for English. T -targeting I nduced L ocal L esions in G enomes (targeted induced local lesions in genomes), has a molecular biological method by which point mutations in a specific gene can be identified specifically. The method combines a standard technique, the mutagenesis using ethyl methanesulfonate (EMS), with a new screening method, which on the detection of mismatch - hybridization by HPLC based. It was optimized using a restriction enzyme , Cel-I , which cuts double strands of DNA at mismatch sites.
The method was in 2000 for the Arabidopsis - genome introduced and has since been to other organisms used.
Traditional mutagenesis screens such as EMS mutagenesis can set point mutations , but the identification of these point mutations in the gene to be mutagenized is very time-consuming.
The TILLING technology enables the testing of many potential mutants at the same time in high throughput. However, mutations can only be found in a known piece of DNA for which specific primers have already been prepared.
An additional application is to find SNPs that are later integrated into the corresponding databases.
TILLING is cited as an alternative to green genetic engineering , as it allows results to be achieved without foreign genes that come close to some of the results from genetic engineering. For example, a potato was created in which the gene that produces undesirable amylose starch is inactivated. Amflora is a product of green genetic engineering with comparable properties . Since the species limit is not exceeded with TILLING, this method is acceptable for organizations such as Greenpeace, which reject green genetic engineering. Novel characteristics such as insect resistance through Bt toxins are not possible.
The treatment of plants with mutation-inducing chemicals in TILLING creates a large number of point mutations. Therefore, not only do the desired traits have to be found, the plants also lose useful traits that are back-crossed with high-performance varieties through years of breeding. In the case of the Amflora alternative, this took six years. In the EU, plants produced by TILLING can be brought onto the market in the same way as conventionally bred plants; in Canada they have to go through an approval process such as genetically modified varieties.
Individual evidence
- ↑ New potatoes bred: alternative to green genetic engineering ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , Stuttgarter Zeitung of January 6, 2010
- ↑ biosicherheit.de Tilling - a lengthy breeding process
literature
- McCallum CM, Comai L, Greene EA, Henikoff S. (2000): Targeted screening for induced mutations. In: Nat. Biotechnol. 18 (4): 455-457. PMID 10748531 doi : 10.1038 / 74542
- McCallum CM, Comai L, Greene EA, Henikoff S. (2000): Targeting induced local lesions IN genomes (TILLING) for plant functional genomics. In: Plant Physiol. 123 (2): 439-442. PMID 10859174 PDF