Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 179 (3), 632-643.e12

The piRNA Response to Retroviral Invasion of the Koala Genome

Affiliations

The piRNA Response to Retroviral Invasion of the Koala Genome

Tianxiong Yu et al. Cell.

Abstract

Antisense Piwi-interacting RNAs (piRNAs) guide silencing of established transposons during germline development, and sense piRNAs drive ping-pong amplification of the antisense pool, but how the germline responds to genome invasion is not understood. The KoRV-A gammaretrovirus infects the soma and germline and is sweeping through wild koalas by a combination of horizontal and vertical transfer, allowing direct analysis of retroviral invasion of the germline genome. Gammaretroviruses produce spliced Env mRNAs and unspliced transcripts encoding Gag, Pol, and the viral genome, but KoRV-A piRNAs are almost exclusively derived from unspliced genomic transcripts and are strongly sense-strand biased. Significantly, selective piRNA processing of unspliced proviral transcripts is conserved from insects to placental mammals. We speculate that bypassed splicing generates a conserved molecular pattern that directs proviral genomic transcripts to the piRNA biogenesis machinery and that this "innate" piRNA response suppresses transposition until antisense piRNAs are produced, establishing sequence-specific adaptive immunity.

Keywords: AKV; KoRV-A; genome invasion; germ-line genome; koala; piRNA; piRNA clusters; retrovirus.

Conflict of interest statement

COMPETING INTERESTS

The authors declare no competing interests.

Similar articles

See all similar articles

Cited by 1 PubMed Central articles

  • PIWI Proteins and piRNAs in the Nervous System
    KW Kim. Mol Cells 42 (12), 828-835. PMID 31838836. - Review
    PIWI Argonaute proteins and Piwi-interacting RNAs (piRNAs) are expressed in all animal species and play a critical role in cellular defense by inhibiting the activation o …

LinkOut - more resources

Feedback