Time-lapse observation of the primary fibroblast cells. Inv::GFP fluorescent and the DIC images of the primary fibroblasts established from the inv/inv, Inv::GFP newborn mouse were observed under confocal microscope every minute for a period of 2 hours. Merged images of the GFP fluorescent and the DIC images are shown. Inv::GFP was detected in the basal body and extended during the formation of primary cilia (see text).