Defective hair formation in calcitonin-like receptor transgenic mice
Abstract
The heterodimeric calcitonin-like receptor (CLR)/receptor-activity-modifying protein 2 (RAMP2) complex is an adrenomedullin (AM) receptor. Here, transgenic mice expressing a V5-CLR in hair follicles have been generated. Skin sections of the transgenic mice and of control littermates have been investigated. The hair diameter of the mice was measured during hair morphogenesis and first hair cycle. Size and weight of V5-CLR transgenic and control mice were indistinguishable. But after day 12, the coat of the transgenic mice is waved. The number of hairs with a small diameter was significantly higher in transgenic mice as compared with control littermates (P < 0.001). There skin sections revealed immunoreactive V5-CLR in the bulb of cycling hair follicles. On in situ hybridization, RAMP2 encoding mRNA colocalized with the V5-CLR protein. Autoradiographic examination showed specific 125I-AM binding in the same place. In conclusion, CLR/RAMP2-overexpressing mice reveal a defined phenotype with thinning of the hairs during postnatal development.
