Abstract
Transposable elements are selfish sequences found in the genomes of almost exclusively all
studied organisms. Over the course of evolution, host organisms fixed molecular machineries
which counteract the multiplication of these highly diverse elements. Among those
machineries, animals utilize the conserved PIWI-interacting RNA (piRNA) pathway. While
core functions of the piRNA pathway are comparable between many species, a wide range of
adaptations are described. Furthermore, many genes of the pathway show signs of rapid
evolution in certain species groups, including Drosophila fruit flies. However, even though
sequence analyses indicate change and selective pressure in closely related Drosophila species,
we do not have an overview of the resulting functional consequences. Here, we analyzed
sequences and systematically tested protein-protein interactions of eleven orthologous genes of
the heterochromatin-specific piRNA transcription network in five Drosophilids. Our yeast-two-
hybrid screening results together with complementary tissue-culture assays and in vivo
interaction data strongly suggest that the rapid evolution of the piRNA pathway in Drosophila
species led to rewiring of essential network components. Furthermore, we developed a high-
throughput genome integration system, a sensitive piRNA pathway malfunction reporter, and
an inducible expression system for insect tissue cultures. These tools will likely allow the
identification of previously undescribed components of the pathway and will proof useful for
other researchers.
studied organisms. Over the course of evolution, host organisms fixed molecular machineries
which counteract the multiplication of these highly diverse elements. Among those
machineries, animals utilize the conserved PIWI-interacting RNA (piRNA) pathway. While
core functions of the piRNA pathway are comparable between many species, a wide range of
adaptations are described. Furthermore, many genes of the pathway show signs of rapid
evolution in certain species groups, including Drosophila fruit flies. However, even though
sequence analyses indicate change and selective pressure in closely related Drosophila species,
we do not have an overview of the resulting functional consequences. Here, we analyzed
sequences and systematically tested protein-protein interactions of eleven orthologous genes of
the heterochromatin-specific piRNA transcription network in five Drosophilids. Our yeast-two-
hybrid screening results together with complementary tissue-culture assays and in vivo
interaction data strongly suggest that the rapid evolution of the piRNA pathway in Drosophila
species led to rewiring of essential network components. Furthermore, we developed a high-
throughput genome integration system, a sensitive piRNA pathway malfunction reporter, and
an inducible expression system for insect tissue cultures. These tools will likely allow the
identification of previously undescribed components of the pathway and will proof useful for
other researchers.
| Original language | English |
|---|
| Publisher | Department of Molecular Biology, Aarhus University |
|---|---|
| Number of pages | 153 |
| Publication status | Published - 29 May 2024 |