PRBB-CRG Sessions Harris Lewin

24/05/202412:00MARIE CURIEPRBB-CRG SessionsHarris LewinUniversity of California Davis & Arizona State University"A Dive into the Breakpoints of Evolution"Host: Roderic GuigóAbstract:Chromosome rearrangements occurring during evolution drive speciation; some are adaptive and positively selected. My laboratory has studied chromosome evolution in mammals for 30 years and developed powerful tools to detect, visualize, and analyze chromosome rearrangements at high resolution. Advances in producing annotated chromosome-scale whole genome assemblies de novo, have led to dramatic improvements in our understanding of chromosome evolution and the genomic consequences of evolutionary chromosome rearrangements. Recently, we have reconstructed the genomes of the most recent common ancestor of all mammals, and ancestors at several principal nodes on the mammalian phylogenetic tree. These ancestral genome reconstructions have permitted the identification of all the major chromosomal inversions, translocations, fusions, and fissions in three super-ordinal lineages of mammals over more than 180 million years of evolution. We discovered differing rates of chromosome evolution in different mammalian lineages, ancient blocks of synteny that have been conserved from the common ancestor of all amniotes for >300 million years due to purifying selection, and the dynamic evolution of genes and non-coding sequences in evolutionary breakpoint regions. The homologous synteny blocks and evolutionary breakpoints were found to have distinct functional genomic landscapes and 3D chromatin conformation is highly conserved within mammalian orders. Our results provide insights into the genomic evolution of mammals, and their relationship to adaptation, speciation, and the origins of cancer.