title: Argonaute2 Protein in Rat Spermatogenic Cells Is Localized to Nuage Structures and LAMP2-Positive Vesicles Surrounding Chromatoid Bodies.
abstract: Localization of Argonaute2 (AGO2) protein--an essential component for the processing of small interfering RNA (siRNA)-directed RNA interference (RNAi) in RNA-induced silencing complex (RISC) in nuage of rat spermatogenic cells--was evaluated by immunofluorescence microscopy (IFM) and immunoelectron microscopy (IEM). AGO2 was shown, for the first time, to be localized to four previously classified types of nuage: irregularly shaped perinuclear granules (ISPGs), intermitochondrial cement (IMC), satellite bodies (SBs), and chromatoid bodies (CBs). Dual IEM staining for AGO2/Maelstrom (MAEL) protein or AGO2/MIWI protein demonstrated that AGO2 is colocalized with MAEL or MIWI proteins in these types of nuage. Dual IFM and IEM staining of AGO2/lysosomal-associated membrane protein 2 (LAMP2) showed that CB in round spermatids are in contact with and surrounded by LAMP2-positive vesicles, whereas nuage in pachytene spermatocytes are not. Taken together, our findings indicate that: (i) AGO2 in pachytene spermatocytes functions in ISPGs, IMC, and SBs; (ii) AGO2 in round spermatids functions in CBs, and that CBs are associated with lysosomal compartments.
authors.affiliation: Nagasaki International University, Sasebo, Japan (YF, YO, HF, SY).
authors.forename: Yuki
authors.initials: Y
authors.lastname: Fujii
authors.affiliation: Nagasaki International University, Sasebo, Japan (YF, YO, HF, SY).
authors.forename: Yuko
authors.initials: Y
authors.lastname: Onohara
authors.affiliation: Nagasaki International University, Sasebo, Japan (YF, YO, HF, SY).
authors.forename: Hideaki
authors.initials: H
authors.lastname: Fujita
authors.affiliation: Nagasaki International University, Sasebo, Japan (YF, YO, HF, SY).
authors.forename: Sadaki
authors.initials: S
authors.lastname: Yokota
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000032:analysis*; D052119:Lysosomal-Associated Membrane Protein 2 / Q000032:analysis*; D008247:Lysosomes / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D013087:Spermatids / Q000166:cytology* / Q000648:ultrastructure; D013090:Spermatocytes / Q000166:cytology* / Q000648:ultrastructure; D013091:Spermatogenesis
chemical_list: C582332:Ago2 protein, rat; D060565:Argonaute Proteins; D052119:Lysosomal-Associated Membrane Protein 2
keywords: Spermatogenesis; argonaute2; chromatoid body; electron microscopy; immunofluorescence microscopy; lysosome; nuage