We sequenced mRNAs and profiled TE expression in six representative species. We found dynamic patterns of TE expression in cichlid gonads and during early development.

Then, we identified TE silencing factors and found an expansion of piwil1 genes in Lake Malawi cichlids, which was likely driven...

Lastly, we find that F-box genes have recurrently captured TE domains, and describe an independent example in zebrafish. This is the initial exploration of the results of our screen, which still surely has interesting biology lurking within.

How did we get to roles in thermotolerance? Directly upstream of the locus of fbxa-215, the most highly expressed A2 gene, we found Helitron TEs, which are known to spread across the genus binding sites for HSF-1, a conserved transcription factor that responds to heat-stress.

We explored the functions of some of the A2 genes most highly expressed in the C. elegans germline and found roles in germ granule localisation, fertility, and thermotolerance. Importantly, the TE-derived HTH domain is required for these processes!

These proteins have a Tc1/Mariner-derived Helix-turn-helix (HTH) domain and an F-box domain. After some phylogenomics detective work, we figured out that the HTH domain was captured by an F-box gene and subsequently expanded, creating a novel class of F-box genes, the A2 family.

TEs often encode the protein machinery they need to mobilise from one locus to another. It is well established that these coding sequences can fuse to host genes, increasing protein diversity and potentially bringing about novel functions.

How do novel proteins emerge? François Jacob compared Evolution to a tinkerer, with novelty arising as a result of rearrangement of available pieces. This can be applied to protein evolution, with novel proteins arising through the shuffling of different pre-existing domains.

First #bluetorial. 🎉🎉 We’re very happy to share our latest biorxiv #preprint, just in time before the holiday season. We explored how transposable elements (TEs) diversify eukaryotic proteomes and found a cool case in nematode F-box genes. #TEsky #evosky #Celegans

Short 🧵 with highlights.