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Centromeric transposable elements and epigenetic status drive karyotypic variation in the eastern hoolock gibbon
Gabrielle A Hartley1,2, Mariam Okhovat3, Savannah J Hoyt1,2
1Institute for Systems Genomics, University of Connecticut, Storrs, CT, USA.
Biorxiv : the Preprint Server for Biology
|September 11, 2024
Summary
Gibbon centromeres show unique features like diverse transposable elements and conserved epigenetic marks, unlike other apes. These genomic attributes likely drive rapid chromosomal evolution in gibbons.
Area of Science:
- Genomics
- Evolutionary Biology
- Molecular Biology
Background:
- Great apes exhibit karyotype stability with minimal large-scale rearrangements.
- Gibbons, in contrast, display a high frequency of chromosomal rearrangements linked to rapid centromere turnover.
Purpose of the Study:
- To characterize the assembled centromeres of the Eastern hoolock gibbon (Hoolock leuconedys).
- To investigate the genomic and epigenetic features contributing to gibbon centromere evolution and chromosomal instability.
Main Methods:
- Centromere characterization using assembled genomic data.
- Analysis of transposable elements (TEs), DNA methylation patterns (CpG methylation), and replication timing.
- Identification of structural variations, topologically associated domain boundaries, and segmental duplications.
Main Results:
- Eastern hoolock gibbon centromeres contain diverse transposable elements, differing from canonical alpha satellites in other apes.
- A conserved CpG methylation centromere dip region was identified, despite the absence of satellite arrays.
- Atypical centromeric features, including protein-coding genes, mismatched replication timing, and large structural variations, were observed.
Conclusions:
- Gibbon centromeres possess unique genomic and epigenetic attributes, including atypical TE composition and conserved methylation patterns.
- A combination of genomic features, such as differentially methylated TEs, TAD boundaries, and segmental duplications, likely contributes to gibbon centromere evolution and chromosome instability.
- The findings suggest a "perfect storm" of genomic factors driving rapid chromosomal evolution in gibbons.
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