Figure 5. Absolute quantification (copies of transcript per ng cDNA) of mRNA expression of gulonolactone oxidase (gulo) from the kidney of Himantura signifer kept in freshwater (FW; control) or exposed to brackish water (salinity 20) for 1 or 6 days after a 4-day progressive increase in salinity.

Results represent mean ± S. E. M. (N = 5). Means not sharing the same letter are significantly different (P<0.05).