title: Identification of MIWI-associated Poly(A) RNAs by immunoprecipitation with an anti-MIWI monoclonal antibody.
abstract: MIWI is one of the PIWI subfamily of proteins mainly expressed in mouse germ cells, and associates with pachytene piRNAs. MIWI has been thought to play an essential role in spermatogenesis and spermiogenesis via biogenesis and/or stability of pachytene piRNAs, retrotransposon silencing, and post-transcriptional regulation of target mRNAs. However, MIWI's detailed role and function are not well understood. In this study, we produced an anti-MIWI mouse monoclonal antibody and identified MIWI-associated poly(A) RNAs by immunoprecipitation from adult mouse testes lysates. Approximately 70% of the MIWI-associated poly(A) RNAs were known mRNAs and 30% of them were unknown non-coding RNAs. These poly(A) RNAs contained piRNA-encoding RNAs transcribed from piRNA cluster regions and piRNA-encoding mRNA, such as Aym1 mRNA. Mature piRNAs specifically encoded in these piRNA-encoding RNAs were generated in pachytene spermatocytes and not detected in Miwi-deficient (Miwi-/-) testes. Moreover, MIWI associated with a large number of known mRNAs whose expression levels were increased in pachytene spermatocytes, and the expression of these mRNAs was decreased in Miwi-/- testes at 20 days postpartum when pachytene spermatocytes were most abundant. These results strongly suggest that MIWI is involved in pachytene piRNA biogenesis and the positive regulation of target mRNA metabolism in pachytene spermatocytes via association with pachytene piRNA precursors and target mRNAs.
authors.affiliation: Life Science Research Laboratories, Wako Pure Chemical Industries Ltd., Hyogo, Japan. nishibu.takahiro@wako-chem.co.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nishibu
authors.forename: Yukinobu
authors.initials: Y
authors.lastname: Hayashida
authors.forename: Saori
authors.initials: S
authors.lastname: Tani
authors.forename: Sadamu
authors.initials: S
authors.lastname: Kurono
authors.forename: Kanako
authors.initials: K
authors.lastname: Kojima-Kita
authors.forename: Ryo
authors.initials: R
authors.lastname: Ukekawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kurokawa
authors.forename: Satomi
authors.initials: S
authors.lastname: Kuramochi-Miyagawa
authors.forename: Toru
authors.initials: T
authors.lastname: Nakano
authors.forename: Kunio
authors.initials: K
authors.lastname: Inoue
authors.forename: Susumu
authors.initials: S
authors.lastname: Honda
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D047468:Immunoprecipitation / Q000379:methods*; D008297:Male; D051379:Mice; D011061:Poly A / Q000235:genetics; D012313:RNA / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics; D013091:Spermatogenesis / Q000235:genetics / Q000502:physiology*; D013737:Testis / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D034741:RNA, Small Interfering; D011061:Poly A; D012313:RNA