Fig. 2. Native gradient polyacrylamide gel showing the AFGP composition in the gastrointestinal fluids and the serum of Arctogadus glacialis and in the serum of Boreogadus saida. Lane 1, stomach fluid, food: crustaceans; lane 2, mid-gut fluid, food: crustaceans; lane 3, hind-gut fluid, food: crustaceans; lane 4, purified AFGP from Dissostichus mawsoni, used as standard; lane 5, A. glacialis serum; lane 6, B. saida serum; lane 7, stomach fluid, food: B. saida; lane 8, mid-gut fluid, food: B. saida; lane 9, hind-gut fluid, food: B. saida. All lanes were loaded with equal amount of AFGP (250 g). The main AFGP sizes for the D. mawsoni standard are indicated. Arrow a indicates an AFGP synthesized by A. glacialis and that is present in all the gastrointestinal fluids; arrow b shows an AFGP in B. saida serum that can be found in all the gastrointestinal fluids; arrow c indicates that AFGP7 has a higher intensity than the AFGP7 in lane 1 (arrow e); arrow d indicates that AFGP8 has higher intensity than AFGP8 in lane 1 (arrow f); arrow g shows the increase in concentration of the high molecular mass AFGPs in the gastrointestinal tract, which originate in the disappearance of the low molecular mass AFGPs.