Research Groups


AGameOfClones for genotyping of transgenic model organisms

March 2018. Many scientists use model organisms, such as worms, mice and insects, to study biological processes – as discoveries made in these often also apply to other species. A common technique is genetic manipulation, in which a foreign gene is inserted into the chromosome of an organism. Such transgenic model organisms are important tools to analyze biological processes or mimic human diseases. Most organisms carry two homologous chromosomes – one inherited from each parent. Newly created transgenic organisms often carry the transgene on only one of the chromosomes. This can be a problem for scientists, as many experiments require individuals that carry the transgene on both. Genetic assays are, therefore, required to identify the genotype.

A team of scientists at Goethe University Frankfurt developed the AGameOfClones vector concept that uses two clearly distinguishable transformation markers embedded in interweaved, but incompatible Lox site pairs. Cre-mediated recombination leads to hemizygous individuals that carry only one marker. In the following generation, heterozygous descendants are identified by the presence of both markers and produce homozygous progeny that are selected by the lack of one marker.

The scientists demonstrated their concept in the red flour beetle, Tribolium castaneum, by creating multiple homozygous transgenic lines suitable for long-term fluorescence live imaging.

Their new approach saves resources and simplifies the handling of transgenic organisms. Since the concept relies on the universal Cre-Lox system, it is expected to work in all diploid model organisms, including for example plants, zebrafish, rodents and other insects. Read more


Publication: Frederic Strobl*, Anita Anderl and Ernst HK Stelzer* (2018) A universal vector concept for a direct genotyping of transgenic organisms and a systematic creation of homozygous lines. eLife 7: e31677.

Ernst Stelzer und Frederic Strobl
Physical Biology, Faculty of Biosciences and Buchmann Institute for molecular Life Sciences
Riedberg Campus, Frankfurt/Main, Germany, E-Mail: ernst.stelzer(at), frederic.strobl(at)