Targeted and tissue-specific transgenesis in rodents.
For many transgenic approaches, a strong and/ or ubiquitous expression is important. As the expression level of a transgene integrated randomly into the genome cannot be predicted, knocking a transgene into a well characterized locus is a good alternative.
PolyGene offers standard knock-ins into well-characterized loci, such as ROSA26 on chromosome 6, for ubiquitous expression of a transgene at moderate levels; alternatively, we use the beta-actin locus, ideally suited for a strong overexpression of transgenes.
An attractive combination involves inserting a transgene with its own promoter into ROSA26, taking advantage of the high recombination rates at that site, and the reliable expression at this locus.
PolyGene’s promoter switch:
In a pretested model, we offer an optional combination of ROSA26 and CAG, with the addition of a verified Cre-excisable stop cassette, and in configurations that include marker genes (e.g., EGFP) to visualize transgene expression in situ. ROSA26 for flexibility and CAG for strong overexpression – up to 100 fold – of transgenes.
Transgenes are predictable in the mouse genome in terms of insertion site and copy numbers. On top of that this is a highly ethical choice: you get better results with less mice.