Large Drosophila germline piRNA clusters are evolutionarily labile and dispensable for transposon regulation.


Type
Article
Change log
Authors
Neubert, Lena K 
Lloyd, Catrin 
Lehmann, Ruth 
Abstract

PIWI proteins and their guiding Piwi-interacting small RNAs (piRNAs) are crucial for fertility and transposon defense in the animal germline. In most species, the majority of piRNAs are produced from distinct large genomic loci, called piRNA clusters. It is assumed that germline-expressed piRNA clusters, particularly in Drosophila, act as principal regulators to control transposons dispersed across the genome. Here, using synteny analysis, we show that large clusters are evolutionarily labile, arise at loci characterized by recurrent chromosomal rearrangements, and are mostly species-specific across the Drosophila genus. By engineering chromosomal deletions in D. melanogaster, we demonstrate that the three largest germline clusters, which account for the accumulation of >40% of all transposon-targeting piRNAs in ovaries, are neither required for fertility nor for transposon regulation in trans. We provide further evidence that dispersed elements, rather than the regulatory action of large Drosophila germline clusters in trans, may be central for transposon defense.

Description
Keywords
chromosome inversions, flamenco, fruit fly, gene silencing, germ cells, gypsy12, heterochromatin, position-effect variegation, sterility, transposable elements, Animals, Animals, Genetically Modified, Argonaute Proteins, Chromosome Deletion, Chromosomes, Insect, DNA Transposable Elements, Drosophila Proteins, Drosophila melanogaster, Evolution, Molecular, Female, Fertility, Gene Expression Regulation, Developmental, Multigene Family, Ovary, RNA Stability, RNA, Small Interfering
Journal Title
Mol Cell
Conference Name
Journal ISSN
1097-2765
1097-4164
Volume Title
81
Publisher
Elsevier BV
Sponsorship
Wellcome Trust (206257/Z/17/Z)
Human Frontier Science Program (HFSP) (CDA00032/2018-C)
Human Frontier Science Program (HFSP)