Fig. 1. Foxn1::dnFgfr2-IIIb transgenic mice develop abnormal hair coats. (A-D) All transgenic mouse lines show strong expression of dnFgfr2-IIIb, as demonstrated by non-radioactive in situ hybridisation. Nevertheless, transcript levels are significantly different, especially between line #53 and lines #42 and #8. The inset in B shows transgene expression in line #53 after extended staining whereas the inset in (A) shows endogenous gene expression of a corresponding wild-type section. The inset in D demonstrates the expression pattern of the endogenous Foxn1 gene, which is identical to that of the dnFgfr2-IIIb transgene under the control of a 30 kb Foxn1 promoter fragment (B-D). (E-H) Strong transgene expression causes a silky hair coat appearance. During early development of the pelage, it also appears to be less dense in transgenic mice when compared with their wild-type littermates; body skin is still visible at day 10 after birth (F). Scale bars: 100 µm.