Functional Redundancy of DICER Co-factors TARBP2 and PRKRA During Murine Embryogenesis Does Not Involve miRNA Biogenesis.
Several in vitro studies suggest canonical miRNA biogenesis requires the DICER co-factors TARBP2 and PRKRA for processing of pre-miRNAs to mature miRNAs. To investigate the roles of TARBP2 and PRKRA in miRNA biogenesis in vivo, and to determine possible functional redundancy, we first compared the phenotypes of Tarbp2 and Prkra single and double-mutants. In contrast to Dicer -/- embryos, which die by E7.5, single Tarbp2 -/- and Prkra -/- mice survive beyond E7.5 and either die peri-natally, or survive and exhibit cranial/facial abnormalities, respectively. In contrast, only a few Tarbp2 -/-; Prkra -/- double-mutants survived beyond E12.5, suggesting genetic redundancy between Tarbp2 and Prkra during embryonic development. Sequencing of miRNAs from single mutant embryos at E15.5, revealed changes in abundance and isomiR type in Tarbp2 -/- , but not Prkra -/- embryos, demonstrating that TARBP2, but not PRKRA, functions in miRNA biogenesis of a subclass of miRNAs, and suggesting that functional redundancy between TARBP2 and PRKRA does not involve miRNA biogenesis.
Genetics 2018 Feb 21 [Epub ahead of print]