Transferrin mRNA in relation to liver iron storage in farmed Atlantic salmon (Salmo salar)

Transferrin mRNA in liver was quantified in farmed Atlantic salmon (Salmo salar) fed three different levels (310-, 65-, and 40 ppm) of dietary iron for 26 weeks. At the time of sampling, the fish fed 40 ppm iron showed symptoms of iron deficiency. Mean values of liver storage iron was reduced from 84 to 12 mg kg(-1) and plasma iron from 2.3 to 1.6 mg l(-1) compared with fish fed 310 ppm iron. No significant difference in transferrin mRNA was observed between normal and iron deficient salmon; the amount of Tf mRNA was not related to the amount of stored iron, either in groups or individual fish. This suggests that there is no iron-modulated transcriptional regulation of liver Tf expression in salmon as there is in chickens and rats.