Out of 30 Gsx2e-CIE;Ai14 animals analyzed, we observed ectopic tdTomato+ cortical cells (few to moderate) in 12 animals. This ratio was similar to what we observed in Gsh2-iCre;Ai14 embryos (1 out of 3) that showed ectopic tdTomato+ cortical cells. Interestingly, transgene expression (as determined by EGFP) in the Gsx2e-CIE;Ai14 animals was consistently normal. Such variable recombination has been reported previously in a number of Cre lines and may be influenced by genetic background (Heffner et al., 2012 (link)).
Three P21 Gsx2e-CIE;Ai14 animals were used for quantifying recombination among different neuronal populations. Both paracapsular and IA (intercalated mass of the amygdala) intercalated cells were counted for quantifying recombination in the amygdala. Cortical interneurons in the somatosensory cortex were quantified to represent recombination among interneuron subtypes. Images for quantification were captured with an Olympus BX50 epifluorescence microscope.
Three P21 Gsx2e-CIE;Ai14 animals were used for quantifying recombination among different neuronal populations. Both paracapsular and IA (intercalated mass of the amygdala) intercalated cells were counted for quantifying recombination in the amygdala. Cortical interneurons in the somatosensory cortex were quantified to represent recombination among interneuron subtypes. Images for quantification were captured with an Olympus BX50 epifluorescence microscope.
