Stress-induced regulation of a human proenkephalin-beta-galactosidase fusion gene in the hypothalamus of transgenic mice.

Transgenic mice expressing an Escherichia coli beta-galactosidase reporter gene under the control of 3 kilobases of human proenkephalin gene 5'-flanking sequence and 1.2 kilobases of 3'-flanking sequence exhibited an anatomically correct pattern of basal and stress-regulated transgene expression within the hypothalamus. Acute osmotic stress and hypovolemia induced transgene expression in neurons within both the paraventricular and supraoptic nuclei. Chronic osmotic stress resulted in dramatic induction of transgene expression in both nuclei. These results demonstrate that the information required for correct hypothalamic expression and stress regulation of the proenkephalin gene is contained within our fusion construct.