Expression of the lipocalin-type prostaglandin D synthase gene in the reproductive tracts of Holstein bulls

The aim of this study was to localize expression of the prostaglandin D syn thase gene in the reproductive tracts of Holstein bulls using northern blot ting and in situ hybridization. For northern blotting, a digoxigenin-labell ed prostaglandin D synthase cDNA probe was used to probe blots containing R NA isolated from the testes, epididymides, vas deferens, ampullae, seminal vesicles, prostate and bulbourethral glands of bulls. The digoxigenin-label led cDNA for the bovine homologue of prostaglandin D synthase hybridized to a single band (approximately 0.9 kb) to RNA samples from the caput, corpus and cauda epididymides, as well as RNA samples from the vas deferens and t he ampulla. The probe also detected a single band in testis samples, althou gh the transcript size was slightly larger (approximately 1.0 kb) than the transcript found in the other tissues. The highest expression of prostaglan din D synthase was observed in the testes and caput epididymides. Prostagla ndin D synthase transcripts were not found in the seminal vesicles or the p rostate or bulbourethral glands using northern blotting. For in situ hybrid ization, antisense and sense riboprobes were synthesized and used to hybrid ize to cryosections obtained from the reproductive tissues of bulls. In sit u hybridization of bull testes showed that prostaglandin D synthase transcr ipts were present within the germ cells in the adluminal compartment of the seminiferous tubules containing round and elongated spermatids, indicating that expression varied with stage of development of the seminiferous tubul es. Prostaglandin D synthase expression was observed in the epithelial cell s of the epididymides with greatest expression occurring in the caput epidi dymidis. Some expression was also observed in the epithelial cells of the v as deferens and a few cells of some lobules in the prostate and bulbourethr al glands. Expression of the prostaglandin D synthase gene was not detected in ampullae or seminal vesicles by in situ hybridization.