Figure 3. Agarose gel electrophoresis of S-crystallin 3’-RACE. Equal concentrations of mRNA used for 3’-RACE was isolated from control octopuses at 180 min of dark or light adaptation and from octopi moved to the opposite lighting conditions at 5 min, 15 min, and 45 min time intervals. Shown in this figure is the 3’-RACE for the 180 min intervals. The asterisks indicate the approximate size of the amplified S-crystallin 3’-RACE fragments. A: Amplification with S-crystallin GSPs generated two fragments at approximately 350 bp and 500 bp in LA and DA octopus retinas (lanes 2 and 3). B: Amplification with S-crystallin nested gene specific primers (NGSPs) generated two fragments at approximately 300 bp and 450 bp, and although barely visible, the 450 bp fragment is present in LA retinas (lanes 2 and 3). The DNA marker sizes (lane 1) in A and B correspond to the fragments of the 100 bp DNA and low molecular weight ladders (Invitrogen and New England BioLabs, Inc.), respectively. The following abbreviations are used in the figure: marker (M), light-adapted (LA), and dark-adapted (DA).