Studies on the expression of the rat growth hormone gene in transfected CV-1 monkey kidney cells and the pituitary gland

The expression of the rat growth hormone gene was studied in transfected CV-1 cells and in the pituitary gland. A 20 kilodalton variant of rat growth hormone was synthesized and secreted by the rat pituitary gland. S1 nuclease mapping analysis of pituitary mRNA indicated that a variant mRNA capable of encoding the 20 kilodalton form was present.;CV-1 cells were transfected with the rat growth hormone gene cloned into the pSV2neo expression vector. Only cell lines with the rat growth hormone gene in the opposite reading frame to that of the neomycin resistance gene expressed immunoreactive and bioactive rat growth hormone. Molecular forms of growth hormone of 22 and 20 kilodaltons were detected. An mRNA encoding the 20 kilodalton form was present at 20% of the levels of the mRNA encoding the 22 kilodalton form. It was shown that the 20 kilodalton variant of rat growth hormone arises by alternative splicing rather than variant gene activity.;Aberrant transcription of the rat growth hormone gene occurred in all of the cell lines. The transcript for rat growth hormone in the expressing cell lines was normal with the exception that the 5...