To act as a negative control the promoterless Pleiades expression vector pEMS1306
(EGFP reporter flanked by minimal frt sites) was introduced by homologous recombination
as single copy insertion into the Hprt1b-m3 locus in the X Chromosome of mouse embryonic
stem cells (ESCs) mEMS1204. The resulting PCR validated four ESC lines, mEMS1503,
mEMS1504, mEMS1516, and mEMS1527. Chimeras were generated using mEMS1503, mEMS1504,
and mEMS1516 and the cell line mEMS1504 was used to generate the mouse strain B6.129P2-Hprt1tm1(mEMS1504)Ems.
The images above are derived from this mouse strain and show no expression as expected
of this negative control.
In a parallel experiment, also to generate a negative control, the promoterless Pleiades
expression vector pEMS1307 (EGFP reporter flanked by full frt sites) was also produced.
Note: CAG positive controls (pEMS1157,
pEMS1277 & pEMS1488) have also been generated.