Species-characteristic and subspecies-characteristic haemoglobins in some tilapiine fishes and a comparative study on their globin chains

Haemoglobins of ten tilapia species of the genera Oreochromis, Sarotherodon and Tilapia, three subspecies of the Nile tilapia, O. niloticus, and an artificial hybrid cross were analysed by isoelectric focusing aimed at characterizing the taxonomic value of these oxygen-binding molecules. Heterogeneous haemoglobin phenotypes were observed in haemolysate samples of all the fishes, and species-characteristic as well as subspecies-characteristic patterns could be identified. F1 hybrids were distinguishable from pure parental specimens. Globin chain studies by AU- and AUT-PAGE systems confirmed the heterogeneity and species specificity observed by isoelectric focusing of the tetrameric molecules. A total of eight different -chains and eight different -chains were detected by AU-PAGE and species-characteristic globin chain variants were shown to occur in almost all species. Globin chain profiles of hybrid specimens were characterized by the presence of all parental globin chain variants. © Rapid Science Ltd. 1998