Fig. 7. In-situ hybridisation analysis of GFP mRNA persistence after electroporation of chick inner ear at stage HH 13 (E2) with HA-N^ICD-IRES-GFP construct. Representative micrographs of whole-mount specimens analysed at 24 hours, 3 days and 7 days post-electroporation. The number of cells expressing GFP mRNA decreases over time, and by 7 days post-electroporation scarcely any such cells are visible. The two cells positive for GFP mRNA in the 7-day specimen (shown enlarged in the insert) might be ones in which the plasmid has survived by integration into the host cell genome.