10.6084/m9.figshare.12145884.v1
Nachen Yang
Nachen
Yang
Satyam Srivastav
Satyam
Srivastav
Qicheng Ma
Qicheng
Ma
Reazur Rahman
Reazur
Rahman
Madoka Chinen
Madoka
Chinen
Elissa Lei
Elissa
Lei
Nelson C. Lau
Nelson
C. Lau
The ‘moving target’ of transposon landscape changes in aging Drosophila
TAGC 2020
2020
transposon
animal aging
piRNA silencing
Genomics
Genetics
Animal Cell and Molecular Biology
Animal Physiology - Cell
Cell Biology
2020-04-20 23:12:51
Poster
https://tagc2020.figshare.com/articles/poster/The_moving_target_of_transposon_landscape_changes_in_aging_Drosophila/12145884
Genetic mechanisms that strongly repress transposable elements (TEs) in young
animals decline during aging because TE transcripts become reactivated. Does TE
transcriptional reactivation during aging then alter and damage the genome? To test this
hypothesis, we quantified Transposon Landscape (TLs) via deeply sequencing genomes of
young and aged Drosophila strains of wild-type and mutant backgrounds. We quantified TLs in
aging whole flies as well as dissected brains, and we validated the feasibility of our approach in
detecting increases in new TE insertions in aging Drosophila genomes when RNAi and Piwi
pathways are compromised.
By also incorporating droplet digital PCR as an important validation methodology for
measuring genomic TE loads, we now show that genetic mutations that strongly reactivate TE
RNA expression only exhibit modest genomic TL changes. Additionally, we examine a new
frontier of extra-chromosomal DNA circles (eccDNAs) as a source of accumulating TE copies
and describe new sequencing methods to quantify eccDNAs in Drosophila. Our analysis
suggests that small RNA surveillance mechanisms still prevent genomic TL expansion despite
the increase in transposon transcripts during aging. However, to combat the natural progression
of increased TE expression during animal aging we show that knocking down the PAF1
complex that regulates RNA Pol II elongation and transcription termination, can reduce aging
related TE expression increases.