Fig. 6. Expression of SkUT mRNA relative to ß-actin mRNA in the dorsal and ventral regions of the kidney of the little skate, Raja erinacea, exposed to 50% seawater for 5 days. The signal of each band was measured by densitometry and presented as a ratio (SkUT/ß-actin) (see Materials and methods). Values are means ± S.E.M., N=4. ^*Significant difference to respective control (Student's t-test, P<0.05).