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Germline piRNAs counteract endogenous retrovirus invasion from somatic cells

ABSTRACT: In metazoan gonads, transposable elements (TEs) mobilization is limited by PIWI-interacting RNAs (piRNAs). These small RNAs originate from specific source loci, the piRNA clusters. piRNAs are known to silence TEs in the cells where they are produced. Endogenous retroviruses (ERVs), a subclass of TEs, pose a particular threat because they are capable of transiting from cell to cell. In this study, we reveal that piRNAs produced locally in germ cells counteract invasion by ERVs arriving from adjacent somatic cells. We reactivated the Drosophila ERVZAMin somatic gonadal cells by deleting, using CRISPR-Cas9 genome editing, its single copy in the somaticflamencopiRNA cluster, while keeping the piRNA pathway fully functional. Upon reactivation,ZAMinvaded the oocytes, resulting in transposition and severe fertility defects. We show that onceZAM-piRNAs are produced in germ cells they counter the invasion. Our study sheds new light on the mechanisms of recognition and regulation of invasive genetic elements, which is essential for the maintenance of genome integrity.

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE235966 | GEO | 2023/08/25

REPOSITORIES: GEO

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Germline piRNAs counteract endogenous retrovirus invasion from somatic cells - Total genomic DNA

Project description:In metazoan gonads, transposable elements (TEs) mobilization is limited by PIWI-interacting RNAs (piRNAs). These small RNAs originate from specific source loci, the piRNA clusters. piRNAs are known to silence TEs in the cells where they are produced. Endogenous retroviruses (ERVs), a subclass of TEs, pose a particular threat because they are capable of transiting from cell to cell. In this study, we reveal that piRNAs produced locally in germ cells counteract invasion by ERVs arriving from adjacent somatic cells. We reactivated the Drosophila ERV ZAM in somatic gonadal cells by deleting, using CRISPR-Cas9 genome editing, its single copy in the somatic flamenco piRNA cluster, while keeping the piRNA pathway fully functional. Upon reactivation, ZAM invaded the oocytes, resulting in transposition and severe fertility defects. We show that once ZAM-piRNAs are produced in germ cells they counter the invasion. Our study sheds new light on the mechanisms of recognition and regulation of invasive genetic elements, which is essential for the maintenance of genome integrity.

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Limited impact of the siRNA pathway on transposable element expression in Aedes aegypti [RNA-seq]

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Limited impact of the siRNA pathway on transposable element expression in Aedes aegypti [ncRNA-seq]

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Euchromatic transposon insertions trigger production of novel pi- and endo-siRNAs at the target sites in the Drosophila germline

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