A targeting construct introduced the following components, in order, to intron 1 of the Gt(ROSA)26Sor gene: CAG-FRT-loxP-stop-loxP-(SNAP-tag/CaaX)-WPRE-pA-AttB-Pr-FRT-Neo-pA-AttP. The SNAP-Tag construct contains a membrane associated CaaX consensus sequence. (J:101977)