Knockout moss

A knockout moss (English knock out " incapacitate ") is a moss plant, in a targeted genetic modification, the so-called gene targeting, specifically one or more genes have been turned off ( gene knockout ). By the loss of a specific gene knockout moss loses the protein encoded by this gene property. By the loss can now infer the function of the off gene. This scientific approach is called reverse genetics, as the researcher wants from a gene to clarify its function. In classical genetics, however, the research is based on a phenotype of the mutant gene and studied. Knockout mosses have a meaning in basic biological research and in biotechnology.

Scientific background

The targeted modification or the targeted gene silencing is based on the integration of a short DNA strand at a precisely determinable position in the genome of the host cell. For this purpose, the DNA piece must have been constructed so that it is identical to the locus at its two ends. Then this DNA is very efficient integrated over Homologous recombination at this locus. According to this principle also knockout mice are produced. So far, this method of targeted gene mutation in the technical language of gene targeting (English gene targeting }) is, patens established in plants only in the moss Physcomitrella, since the efficiency of homolog recombination here is several orders of magnitude higher than in seed plants.

Method

To specifically modify genes in mosses, the DNA construct is incubated with protoplasts and polyethylene glycol. Since mosses are haploid organisms, regenerating Moosfilamente ( protonemata ) can be checked directly on gene targeting, for example, within just 6 weeks using PCR methods.

Examples

Plastidenteilung

The first scientific publication on the function elucidation of a previously unknown gene using a knockout moss was presented by Reski and employees in 1998. Through a knockout of the ftsZ gene they succeeded the first functional identification of a major for the division of organelles in eukaryotes protein.

Protein modifications

By knockout of several genes Physcomitrella plants were prepared, where the plant-specific glycosylation of proteins, an important post-transcriptional modification, is missing. These knock-out mosses are used to produce complex biopharmaceuticals (Molecular Pharming ) used in moss bioreactors.

Mutant collection

In cooperation with BASF Reski and staff have created a mutant collection of knockout moss, which is used for gene identification.