Crollius, H. R. | Search bioRxiv

bioRxiv2025

Salmonids reveal principles of regulatory evolution following autotetraploidization

Early vertebrate autotetraploidization events may have enabled major innovations by expanding the genetic material for functional diversification, yet their ancient timing obscures how genome doubling reshaped gene regulatory evolution. Salmonids provide a unique window to these mechanisms, because they experienced a comparatively recent autotetraploidization and are earlier in the rediploidization process - which creates new genes and regulatory elements during evolution. Here, using large-scale multiomics spanning embryonic and adult tissues in two salmonids, we investigate gene regulatory evolution following genome doubling and rediploidization, which we show is governed by developmental and tissue-specific context, with a period of maximal constraint at advanced stages of embryogenesis. This work advances understanding of vertebrate genome evolution, while providing an open resource supporting salmonid aquaculture and conservation.

evolutionary biology↗

bioRxiv2022

Reconstruction of hundreds of reference ancestral genomes across the eukaryotic kingdom

Ancestral sequence reconstruction is a fundamental aspect of molecular evolution studies, and can trace small-scale sequence modifications through the evolution of genomes and species. In contrast, fine-grained reconstructions of ancestral genome organisations are still in their infancy, limiting our ability to draw comprehensive views of genome and karyotype evolution. Here we reconstruct the detailed gene contents and organisations of 624 ancestral vertebrate, plant, fungi, metazoan and protist genomes, 183 of which are near-complete chromosomal reconstructions. Reconstructed ancestral genomes are similar to their descendants in terms of gene content as expected and agree precisely with reference cytogenetic and in silico reconstructions when available. By comparing successive ancestral genomes along the phylogenetic tree, we estimate the intra- and inter-chromosomal rearrangement history of all major vertebrate clades at high resolution. This freely available resource introduces the possibility to follow evolutionary processes at genomic scales in chronological order, across multiple clades and without relying on a single extant species as reference.

evolutionary biology↗