English: F1-litter of Venus-fluorescent piglets. Breeding of founder boar #503 with a wild-type sow resulted in a litter of eight piglets. Founder #503 carries three single copy transposon integrations. The calculated ratio of transgenic offspring is 87.5% (permutations of the three integrants), if the integration sites represent indeed single copy events and are independently inherited. The piglets are shown under illumination with (i) normal light, (ii) blue light excitation and (iii) blue light excitation and emission filter. Note the different fluorescence intensities at specific excitation (condition iii). The fluorescence intensities directly correlated with the number of transposon copies as determined by Southern blotting. The two non-transgenic piglets are only vaguely visible under fluorescence recording.