| First Author | Prabhakar A | Year | 2019 |
| Journal | PLoS One | Volume | 14 |
| Issue | 3 | Pages | e0213326 |
| PubMed ID | 30913225 | Mgi Jnum | J:273457 |
| Mgi Id | MGI:6287503 | Doi | 10.1371/journal.pone.0213326 |
| Citation | Prabhakar A, et al. (2019) Leaky expression of channelrhodopsin-2 (ChR2) in Ai32 mouse lines. PLoS One 14(3):e0213326 |
| abstractText | Optogenetics enables the selective activation of genetically-targeted neuronal populations using light-sensitive ion channels. Genetic strategies using Cre-dependent mouse strains, especially the Ai32 line expressing Channelrhodopsin (ChR2)-EYFP fusion protein, have been a popular means to drive opsin expression in a cell-type specific manner. Here we report a low level of leaky 'off-target' (Cre-independent) ChR2-EYFP expression in Ai32/Ai32 homozygous mice throughout the nervous system. This leaky off-target expression was characterized in multiple prevalent nervous system regions using anti-EYFP immunostaining. Expression of full-length ChR2-EYFP protein was confirmed using immunoprecipitation followed by Western blotting. Notably, light stimulation of these ChR2-EYFP expressing neurons in the spinal cord dorsal horn did not induce detectable photocurrents in juvenile 4-week old mice. Given the wide use of the Ai32 line by many labs, our results suggest researchers should be vigilant of possible off-target ChR2-EYFP expression in their region of interest, especially when generating Ai32/Ai32 homozygotes to drive high levels of ChR2-EYFP expression in adult mice. |
