Fluoresence in testes and sperm from B. tryoni transformed with vector 1261. (a) A testis dissected from a 1261 transformed fly. Top, white light; bottom, with dsRED Ultra filter. (b) and (c) Confocal images of sperm from a 1261 transformed male (b) and a non-transformed male (c). Sperm were observed using an inverted Zeiss LSM 5 laser scanning confocal microscope. In each case left is the fluorescence image, the right image is bright field.