Discovery and Characterization of piRNAs in the Human Fetal Ovary.
Piwi-interacting RNAs (piRNAs), a class of 26- to 32-nt non-coding RNAs (ncRNAs), function in germline development, transposon silencing, and epigenetic regulation. We performed deep sequencing and annotation of untreated and periodate-treated small RNA cDNA libraries from human fetal and adult germline and reference somatic tissues. This revealed abundant piRNAs originating from 150 piRNA-encoding genes, including some exhibiting gender-specific expression, in fetal ovary and adult testis-developmental periods coinciding with mitotic cell divisions expanding fetal germ cells prior to meiotic divisions. The absence of reads mapping uniquely to annotated piRNA genes demonstrated their paucity in fetal testis and adult ovary and absence in somatic tissues. We curated human piRNA-expressing regions and defined their precise borders and observed piRNA-guided cleavage of transcripts antisense to some piRNA-producing genes. This study provides insights into sex-specific mammalian piRNA expression and function and serves as a reference for human piRNA analysis and annotation.
The Program for Early and Recurrent Pregnancy Loss (PEARL), Department of Obstetrics & Gynecology and Women's Health, The Albert Einstein College of Medicine, Bronx, NY 10461, USA; Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA. Electronic address: zev.williams@einstein.yu.edu.
Zev
Z
Williams
Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
Pavel
P
Morozov
Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
Aleksandra
A
Mihailovic
Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
Carolina
C
Lin
Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
Pavan Kumar
PK
Puvvula
Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
Stefan
S
Juranek
The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, New York, NY 10021, USA.
Zev
Z
Rosenwaks
Howard Hughes Medical Institute and Laboratory for RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA. Electronic address: ttuschl@mail.rockefeller.edu.
Thomas
T
Tuschl
D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008297:Male; D010053:Ovary / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics*; D013737:Testis / Q000378:metabolism
D034741:RNA, Small Interfering