Southern blot analysis of Atlantic cod genomic DNA showing presence of AFGP coding sequences. Taq I digested genomic DNA (~10–15 μg) from Atlantic cod (lanes 1–14) and polar cod (lanes 15–17) hybridized strongly to a polar cod B. saida AFGP coding sequence probe. Atlantic cod individuals include Norwegian coastal cod (NCC) and North East Arctic cod (NEAC) from the Finnmark coast and marginal Barents Sea sites: (lanes 1–3) N69° 26.91′ E19° 37.56′; (lanes 4–5) N69° 58.34′ E30° 2.37′; (lanes 6–8) N70° 7.24′ E30° 48.47′; (lanes 9–13) N71° 11.93′ E27° 59.29′, and one individual (lane 14) from Øresund, Denmark. NEAC and NCC are distinguished by their Pan I genotype, BB and AA respectively as indicated, while AB can either be NEAC or NCC. For comparison, the related freshwater cod Lota lota (lane 18) that does not have AFGP shows no hybridization.