Figure 7. Differential functions of Foxn1 in TECs versus keratinocytes.

(A) Gene expression comparisons were made with 3 independently isolated fetal thymi, obtained from E13.5 embryos of the indicated genotypes. The presence of a hypoplastic thymi was confirmed by subsequent genotyping to select for Foxn1⁹³³ and Foxn1¹⁰⁸⁹ alleles. A heatmap revealed a subset of up- and downregulated genes, with a selection criterion of a 1.5-fold difference as a cutoff. (B) Data on differentially expressed transcripts, particularly those with reported functions in embryonic thymic development. (C) Images of postembryonic day–4 mice of the indicated genotypes were processed with bright-field imaging on a dark background, revealing hair and fur extending out from the skin. Scale bars: 1 mm. (D and E) qRT-PCR was performed to compare the levels of genes previously reported to be involved in hair shaft extension. This was performed to compare (D) 3 littermate controls and 3 Foxn1^933/933 mice and, in a separate experiment, (E) 3 controls and 3 Foxn1^933/1089 mice. The data shown reflect results from 1 of 2 independent experiments with 2 to 3 mice per group. ^#P = 0.02, ^##P = 0.001, and ^####P = 0.00006, by Student’s t test. There were no significant differences in any of the transcripts compared between the 2 mouse lines in E.