title: Most regions of mouse epididymis are able to phagocytose immature germ cells.
abstract: The role of the epididymis as a quality control organ in preventing infertile gametes entering the ejaculate has been extensively explored, and it has been suggested that a specific region of mammalian epididymis is able to phagocytose abnormal germ cells. This study examines whether the epithelium of certain zones of the mouse epididymis can act as a selection barrier by removing immature germ cells from the lumen by phagocytosis. To detect the presence of immature germ cells in the epididymis, we generated transgenic mice expressing enhanced green fluorescent protein under the deleted in azoospermia-like (mDazl) promoter to easily identify immature germ cells under fluorescence microscopy. Using this technique, we observed that during the first stage of spermatogenesis in prepuberal mice, a wave of immature germ cells is released into the epididymis and that the immature epididymis is not able to react to this abnormal situation. By contrast, when immature germ cells were artificially released into the epididymis in adult mice, a phagocytic response was observed. Phagosomes appeared inside principal cells of the epididymal epithelium and were observed to contain immature germ cells at different degradation stages in different zones of the epididymis, following the main wave of immature germ cells. In this paper, we describe how the epididymal epithelium controls sperm quality by clearing immature germ cells in response to their artificially induced massive shedding into the epididymal lumen. Our observations indicate that this phenomenon is not restricted to a given epididymis region and that phagocytic capacity is gradually acquired during epididymal development.
authors.affiliation: Department of Animal Reproduction, INIA, Avenida Puerta de Hierro 12, Local 10, Madrid 28040, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Ramos-Ibeas
authors.forename: E
authors.initials: E
authors.lastname: Pericuesta
authors.forename: R
authors.initials: R
authors.lastname: Fernández-González
authors.forename: M A
authors.initials: MA
authors.lastname: Ramírez
authors.forename: A
authors.initials: A
authors.lastname: Gutierrez-Adan
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002461:Cell Line, Transformed; D003078:Colchicine / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D004822:Epididymis / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D010587:Phagocytosis / Q000187:drug effects; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D011401:Promoter Regions, Genetic / Q000187:drug effects; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D055101:Semen Analysis; D013079:Sperm Maturation / Q000187:drug effects; D013087:Spermatids / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D050257:Tubulin Modulators / Q000494:pharmacology
chemical_list: D015415:Biomarkers; C508515:DAZL protein, mouse; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D050257:Tubulin Modulators; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D003078:Colchicine