C. Jagger et al., The porcine calcitonin receptor promoter directs expression of a linked reporter gene in a tissue and developmental specific manner in transgenic mice, ENDOCRINOL, 140(1), 1999, pp. 492-499
We have investigated the transcriptional regulation of the porcine calciton
in (CT) receptor (pCTR) promoter in transgenic mice. A construct containing
2.1 kb pCTR 5' flanking region, fused to a P-galactosidase (lacZ) gene, wa
s employed for the production of transgenic mice. At 11.5 days of developme
nt lacZ expression was observed in the embryonic brain and spinal cord. By
15.5 days post fertilization, lacZ expression was detected in the developin
g mammary gland, external ear, cartilage primordium of the humerus, and ant
erior naris (nostril). RT-PCR on RNA from these fetal tissues showed endoge
nous mouse CTR (mCTR) expression. In neonatal and adult transgenics, lacZ e
xpression was silenced, except in brain, spinal cord, and testis (adults on
ly). Endogenous mCTR gene expression and pCTR promoter activity were corepr
essed in the same tissues from adult mice. No pCTR promoter activity was de
tected in the kidney or bone of transgenic animals. This suggests that addi
tional DMA sequences may be required for pCTR promoter activity in these ti
ssues. From these results, we conclude that the pCTR promoter is active onl
y in tissues expressing endogenous mCTR. Many of the these tissues represen
t previously unknown sites of CTR gene expression. Finally, the development
al regulation of pCTR/mCTR in tissues such as breast and cartilage primordi
um suggests that CTRs may play a role in the morphogenesis of these tissues
.