As the cbh1 5′ homology region was deleted during the construction of pTrEno, the expression cassette liberated by restriction digest with SbfI and XhoI does not target via homology and instead serves as a random integration cassette.
The establishment of high producer is an important issue in Chinese hamster ovary (CHO) cell culture considering increased heterogeneity by the random integration of a transfected foreign gene and the altered position of the integrated gene.
The TCGO mouse line was produced by the random integration of a reporter cassette in the mouse genome (reported in a manuscript currently being revised).
To overcome this deficiency, we screened a large collection of transgenic strains that were generated by random integration of a gene-trapping construct bearing a Gal4FF driver (Kawakami et al., 2010).
Our new CHO host cell line DUKX-B11 F3/F was developed by random integration of a RMCE-competent cassette followed by target site selections to guarantee a homogenous cell population with an expedient cassette exchange and transcription potential.
Transgenesis by random integration of a transgene into the genome of a zygote has become a reliable and powerful method for the creation of new mouse strains that express exogenous genes, including human disease genes, tissue specific reporter genes or genes that allow for tissue specific recombination.
Furthermore, when R4 attB and attP sites are placed into the human genome, either by random integration or at a specific sequence by using the φC31 integrase, they act as targets for integration of incoming plasmids bearing R4 att sites.
Secondly, Cre transgenic mouse strains are mostly generated by random integration of a DNA construct comprising promoter and Cre cDNA into the host DNA.
The Tg[gSAGFF202A] line was generated by random integration of a gene-trap construct (Asakawa et al., 2008).
To determine whether the gene body methylation status in the transgene of line E is determined by the Ci-Trl promoter, we examined a parallel transgenic line, line F. Line F has the same transgene as line E, but it is inserted at a different genomic locus by random integration (genomic position KHC2 275935).
