Abstract
We have generated 2 transgenic mouse lineages expressing a mWAP/hGH fusion gene where 5' sequence from the mouse whey acidic protein (mWAP) gene is linked to the coding region for human growth hormone (hGH). In the present study, we investigated whether hGH was synthesized in the mammary gland of the transgenic mice and secreted into milk, and whether physiological functions of the transgenic mice were affected by the expression of the transgenes or not. Milk taken from female mice of the transgenic lineages contained about 4.77±0.1 μg/ml (n=4) hGH in average. The hGH was also detected in plasma of the transgenic mice expressing the transgene. The plasma hGH was probably derived from several organs, including submandibular glands, pancreases and tongues as well as mammary glands. The results suggested that expression of the transgenes were probably higher in organs with exocrine functions. In addition, hGH was produced in the brain. Transgenic females derived from one of the founder males showed the sterility accompanied by obesity, insulinemia and hyperglycemia. Histological examination confirmed that the number of azocarmine-positive cells which represent GH secreting-cells in the anterior hypophysis was dramatically reduced in the sterile transgenic females compared to the control mice. The ovary showed signs of pronounced disorders accompanied by failure of follicular growth and by inability of the corpus luteum formation.
