title: Widespread expression of piRNA-like molecules in somatic tissues.
abstract: Piwi-interacting RNA (piRNA) are small RNA abundant in the germline across animal species. In fruit flies and mice, piRNA have been implicated in maintenance of genomic integrity by transposable elements silencing. Outside of the germline, piRNA have only been found in fruit fly ovarian follicle cells. Previous studies have further reported presence of multiple piRNA-like small RNA (pilRNA) in fly heads and a small number of pilRNA have been reported in mouse tissues and in human NK cells. Here, we analyze high-throughput small RNA sequencing data in more than 130 fruit fly, mouse and rhesus macaque samples. The results show widespread presence of pilRNA, displaying all known characteristics of piRNA in multiple somatic tissues of these three species. In mouse pancreas and macaque epididymis, pilRNA abundance was compatible with piRNA abundance in the germline. Using in situ hybridizations, we further demonstrate pilRNA co-localization with mRNA expression of Piwi-family genes in all macaque tissues. Further, using western blot, we have shown the expression of Miwi protein in mouse pancreas. These findings indicate that piRNA-like molecules might play important roles outside of the germline.
authors.affiliation: Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Chinese Academy of Sciences, 320 Yueyang Road, 200031, Shanghai, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yan
authors.forename: Hai Yang
authors.initials: HY
authors.lastname: Hu
authors.forename: Xi
authors.initials: X
authors.lastname: Jiang
authors.forename: Vera
authors.initials: V
authors.lastname: Maierhofer
authors.forename: Elena
authors.initials: E
authors.lastname: Neb
authors.forename: Liu
authors.initials: L
authors.lastname: He
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Hu
authors.forename: Hao
authors.initials: H
authors.lastname: Hu
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Philipp
authors.initials: P
authors.lastname: Khaitovich
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D008253:Macaca mulatta; D008297:Male; D051379:Mice; D034741:RNA, Small Interfering / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D034741:RNA, Small Interfering