PT  - JOURNAL ARTICLE
AU  - Hanna M. Sahlström
AU  - Alex K. Datsomor
AU  - Øystein Monsen
AU  - Torgeir R. Hvidsten
AU  - Simen Rød Sandve
TI  - Functional validation of transposable element derived <em>cis</em>-regulatory elements in Atlantic salmon
AID  - 10.1101/2022.11.02.514921
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.11.02.514921
4099  - http://biorxiv.org/content/early/2022/11/04/2022.11.02.514921.short
4100  - http://biorxiv.org/content/early/2022/11/04/2022.11.02.514921.full
AB  - Background Transposable elements (TEs) are hypothesized to play important roles in shaping genome evolution following whole genome duplications (WGD), including rewiring of gene regulation. In a recent analysis, duplicate gene copies that had evolved higher expression in liver following the salmonid WGD ~100 million years ago were associated with higher numbers of predicted TE-derived cis-regulatory elements (TE-CREs). Yet, the ability of these TE-CREs to recruit transcription factors (TFs) in vivo and impact gene expression remains unknown.Results Here, we evaluated the gene regulatory functions of 11 TEs using luciferase promoter reporter assays in Atlantic salmon (Salmo salar) primary liver cells. Canonical Tc1-Mariner elements from intronic regions showed no or small repressive effects on transcription. However, other TE-derived cis-regulatory elements upstream of transcriptional start sites increased expression significantly.Conclusion Our results question the hypothesis that TEs in the Tc1-Mariner superfamily, which were extremely active following WGD in salmonids, had a major impact on regulatory rewiring of gene duplicates, but highlights the potential of other TEs in post-WGD rewiring of gene regulation in the Atlantic salmon genome.Competing Interest StatementThe authors have declared no competing interest.