Expression of FOXL2 and SOX9 one month after tamoxifen injection into Dmrt1flox/flox adult males (8 weeks and older) carrying inducible ubiquitous cre transgene UBC-cre/ERT2. (a,b) Sertoli cells in control testis express SOX9 but not FOXL2. (c–f) Mutant testis has Sertoli-like cells expressing SOX9 or SOX9 and FOXL2 (inset, d) and granulosa-like cells expressing only FOXL2 (inset, f). (g,h) FOXL2-positive cells in control ovary have DAPI morphology similar to FOXL2 single-positive cells of mutant testis. FOXL2-positive cells in mutant testis resemble granulosa cells: they lack the tripartite nucleoli of Sertoli cells, have smaller and more rounded nuclei, and have more punctate DAPI staining. UBC-cre/ERT2 also deletes Dmrt1 in germ cells, causing precocious meiosis12; after one month germ cells are nearly absent. Scale bars: 20 μm.