Figure 5

Phenotypic analysis of mice carrying Foxn1^ex9lacZand Foxn1^ex9crealleles. A, Semi-quantitative RT-PCR of Foxn1 RNA in thymi from heterozygous and homozygous Foxn1^ex9creor Foxn1^ex9lacZnewborn mice. Both the 586 bp Foxn1 full-length product and the 124 bp exon 2–4 spliced product are first seen at 24 cycles in all genotypes. B-E, Keratin 5 and keratin 8 expression in the E16.5 thymus. Transverse sections through E16.5 thymic lobes from (B) wild-type, (C) Foxn1^+/ex9cre, (D) Foxn1^+/ex9lacZand (E) Foxn1^{ex9lacZ/ex9lacZ}embryos. Keratin 8 is shown in green and marks cortical epithelial cells, while keratin 5 marks medullary epithelial cells and is shown in red. F, FACS analysis of thymocytes from Foxn1^ex9lacZand Foxn1^ex9cremice. Thymocytes from newborn mice were stained with anti-CD4-APC, anti-CD8-FITC, anti-CD44-PE, and anti-CD25-Biotin followed by Streptavidin-PerCP. The upper panels show expression of CD4 and CD8 on total thymocytes. The lower panels show expression of CD44 and CD25 on the gated CD4^- CD8^- subpopulation.