Fig. 1. Expression and localization of MOR23-encoding transcripts in mouse testis. (A) Tissue distribution of MOR23-encoding transcripts. Expression of MOR23 was assessed by RT-PCR. F, female; G3P-DH, glyceraldehyde-3-phosphate dehydrogenase; M, male. (B-E) The distribution pattern of the MOR23-encoding transcript was analysed by in situ hybridization. (B,D) Detection of MOR23-encoding mRNA with an antisense probe. MOR23-encoding mRNA was detected in a few seminiferous tubes using a TSA biotin system with AP- or HRP-conjugated streptavidin. (C) Control for nonspecific staining using a MOR23 sense probe; no signal was observed. (E) A high-magnification image of the MOR23 antisense probe staining indicates that the MOR23-encoding transcript is localized in spermatogenic cells. Hybridization signals detected with AP-streptavidin followed by NBT/BCIP are stained purple (B,C), whereas those detected with HRP-streptavidin followed by DAB are stained brown and nuclei are counterstained with methyl green (D,E). Scale bars, 100 µm (B-D), 20 µm (E).