We crossed SynCre mice with Tg403-loxp-rtTA mice, but all the pups ended up with either one of the genes, not both together, as confirmed by genotyping tests. Has this ever happened to anyone else?
The number of pups seems to be within the normal range, but the peculiar aspect is the change in results over time. Initially, the mating between the colonies was successful, yielding offspring with both genes present. However, after encountering difficulties with the SynCre colony, we separated the colonies for a period. Upon reintroducing them for mating, the desired outcome ceased, with instances where, for instance, a SynCre male crossed with a Tg-loxp-... female resulted in 7 pups, where 3 had only the Tg... and 4 had SynCre only.