INSITU DETECTION AND DISTRIBUTION OF STANNIOCALCIN MESSENGER-RNA IN THE CORPUSCLES OF STANNIUS OF SOCKEYE-SALMON, ONCORHYNCHUS-NERKA

Stanniocalcin (STC) gene expression was examined in the corpuscles of Stannius of sockeye salmon by in situ hybridization. Generally, the STC gene was not expressed uniformly in all cells of the corpuscles of Stannius. However, in cases where gene expression was uniform throughout a gland, it appeared that virtually all cells contained STC mRNA, thereby supporting the 'one cell type' hypothesis for the corpuscles of Stannius. Correlative immunocytochemistry on adjacent tissue sections indicated that cellular levels of stored hormone paralleled the distribution of STC mRNA. Stanniocalcin mRNA was undetectable in numerous other salmon tissues, thereby further supporting the notion that the STC gene is expressed exclusively in the corpuscles of Stannius.