Fig. 2. Localization of DACH2 and FAM9A in a testis from an adult man with Klinefelter syndrome (KS).

IHC staining with antibodies against DACH2 and FAM9A of a testis from an adult man with KS (which is the same sample as aKS3 used for RNA-sequencing). DACH2 was expressed in a fraction of nuclei both in type A (mature) Sertoli cell-only (SCO) tubules (a) and type B (immature) SCO tubules (b). The same pattern was seen in another KS testis, aKS1, also used for the transcriptome profiles (data not shown). In the CMC testis (n = 3) (exemplified here aCMC1 used for RNA-sequencing), DACH2 was only expressed weakly (c, d) In adult KS, FAM9A was expressed in Leydig cells with varying intensity (e) and in all Sertoli cell nuclei (f). Immunofluorescence staining showed that FAM9A and INSL3 were expressed by two populations of Leydig cells with limited overlap. Scale bars correspond to 50 µm