Molecular basis for multiplicity of Pacific salmon hemoglobins: evidence for in vivo existence of molecular species with up to four different polypeptides

1. 1. The seven major hemoglobin zones of Oncorhynchus nerka were designated together with their subunit structures, in parentheses, HbNerka Sa(αSsαSfβ2Sf), HbNerka Sb(αSsαSfβSsβSf), HbNerka Sc(αSsαSfβ2Ss), HbNerka Fa(α2FβFmβFf), HbNerka Fb(α2Fβ2Ff), HbNerka Fc(α2FβFsβFf), HbNerka Fd(α2Fβ2Fs). At least eight structural genes code for the eight polypeptides involved. 2. 2. Juvenile O. nerka lacks polypeptide βSs and hence hemoglobin HbNerka Sb and HbNerka Sc but possesses an additional polypeptide βFm resulting in hemoglobin HbNerkaFa. 3. 3. The heterozygous HbNerkaFc is not only present in hemolysates near neutral pH, but also forms HbNerkaFb and HbNerkaFd in vitro at pH 8·5. No evidence of hybridization was found between the cathodal and anodal hemoglobins. 4. 4. The hemoglobins of O. keta, O. kisutch, O. gorbuscha, O. tshawytscha and Salmo gairdneri also consist of molecular species with up to 4 different polypeptides.