UMass Chan Medical School Faculty Publications

Title

piRNA-independent transposon silencing by the Drosophila THO complex

UMMS Affiliation

Program in Molecular Medicine; Program in Bioinformatics and Integrative Biology; Graduate School of Biomedical Sciences

Publication Date

2021-09-27

Document Type

Article

Disciplines

Amino Acids, Peptides, and Proteins | Cell and Developmental Biology | Nucleic Acids, Nucleotides, and Nucleosides

Abstract

piRNAs guide Piwi/Panoramix-dependent H3K9me3 chromatin modification and transposon silencing during Drosophila germline development. The THO RNA export complex is composed of Hpr1, Tho2, and Thoc5-7. Null thoc7 mutations, which displace Thoc5 and Thoc6 from a Tho2-Hpr1 subcomplex, reduce expression of a subset of germline piRNAs and increase transposon expression, suggesting that THO silences transposons by promoting piRNA biogenesis. Here, we show that the thoc7-null mutant combination increases transposon transcription but does not reduce anti-sense piRNAs targeting half of the transcriptionally activated transposon families. These mutations also fail to reduce piRNA-guided H3K9me3 chromatin modification or block Panoramix-dependent silencing of a reporter transgene, and unspliced transposon transcripts co-precipitate with THO through a Piwi- and Panoramix-independent mechanism. Mutations in piwi also dominantly enhance germline defects associated with thoc7-null alleles. THO thus functions in a piRNA-independent transposon-silencing pathway, which acts cooperatively with Piwi to support germline development.

Keywords

H3K4me2, H3K9me3, Piwi, THO, Thoc7, germline development, piRNA, transcriptional silencing, transposon silencing

DOI of Published Version

10.1016/j.devcel.2021.08.021

Source

Zhang G, Yu T, Parhad SS, Ho S, Weng Z, Theurkauf WE. piRNA-independent transposon silencing by the Drosophila THO complex. Dev Cell. 2021 Sep 27;56(18):2623-2635.e5. doi: 10.1016/j.devcel.2021.08.021. Epub 2021 Sep 20. PMID: 34547226; PMCID: PMC8567991. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

Developmental cell

PubMed ID

34547226

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