Fig. 4. Tissue distribution of (A) GLUT4, (B) GLUT2 and (C) GPDH in Atlantic cod. Tissues from a single fed juvenile Atlantic cod were analyzed by qRT-PCR for expression of GLUT4, GLUT2 and GPDH. Expression levels of the target gene were normalized to 18S rRNA. Units represent the relative expression of normalized target gene with respect to a calibrator sample, which in this case is the tissue that expresses the target gene at the lowest detectable level.