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P Transposable Elements in Drosophila and other Eukaryotic Organisms
Sharmistha Majumdar1, Donald C Rio1
1Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3204.
Microbiology Spectrum
|June 25, 2015
Summary
P transposable elements, key to hybrid dysgenesis in Drosophila, are ancient DNA transposons. Surprisingly, related THAP9 genes in humans and zebrafish encode active transposases, suggesting conserved transposition mechanisms.
Area of Science:
- Genetics
- Molecular Biology
- Evolutionary Biology
Background:
- P transposable elements in Drosophila cause hybrid dysgenesis, a phenomenon linked to the piRNA pathway.
- P elements revolutionized Drosophila molecular genetics, serving as model systems for eukaryotic transposition.
- Biochemical studies revealed unique mobilization mechanisms, including specific DNA breaks and GTP cofactor use by P element transposase.
Purpose of the Study:
- To investigate the evolutionary conservation and functional activity of P element-like sequences in eukaryotic genomes.
- To determine if P element transposase-related genes in other species retain transposition capabilities.
Main Methods:
- Bioinformatic analysis of genome sequencing data to identify P element-like sequences and transposase-related genes (THAP9).
- Functional assays in human and Drosophila cells to test the transposition activity of THAP9 proteins using the Drosophila P element transposon.
Main Results:
- P element-like transposable elements and THAP9 genes are widespread across eukaryotic genomes, including vertebrates.
- Human and zebrafish THAP9 genes were found to actively promote the transposition of the Drosophila P element DNA.
- This indicates that THAP9 genes encode functional P element transposase proteins.
Conclusions:
- P element transposase-related genes (THAP9) are ancient and conserved across diverse eukaryotes.
- These THAP9 proteins retain the ability to mobilize the Drosophila P element, highlighting conserved transposition mechanisms.
- The findings suggest a broader role for THAP9 proteins in eukaryotic transposition and genome dynamics.
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