Genomic analyses of the Linum distyly supergene reveal convergent evolution at the molecular level

Autor: Juanita Gutiérrez-Valencia, Marco Fracassetti, Emma L. Berdan, Ignas Bunikis, Lucile Soler, Jacques Dainat, Verena E. Kutschera, Aleksandra Losvik, Aurélie Désamoré, P. William Hughes, Alireza Foroozani, Benjamin Laenen, Edouard Pesquet, Mohamed Abdelaziz, Olga Vinnere Pettersson, Björn Nystedt, Adrian C. Brennan, Juan Arroyo, Tanja Slotte
Jazyk: angličtina
Předmět:
Zdroj: Current Biology
Current Biology, 2022, Vol.32(20), pp.4360-4371 [Peer Reviewed Journal]
ISSN: 0960-9822
DOI: 10.1016/j.cub.2022.08.042
Popis: Supergenes govern multi-trait-balanced polymorphisms in a wide range of systems; however, our understanding of their origins and evolution remains incomplete. The reciprocal placement of stigmas and anthers in pin and thrum floral morphs of distylous species constitutes an iconic example of a balanced polymorphism governed by a supergene, the distyly S-locus. Recent studies have shown that the Primula and Turnera distyly supergenes are both hemizygous in thrums, but it remains unknown whether hemizygosity is pervasive among distyly S-loci. As hemizygosity has major consequences for supergene evolution and loss, clarifying whether this genetic architecture is shared among distylous species is critical. Here, we have characterized the genetic architecture and evolution of the distyly supergene in Linum by generating a chromosome-level genome assembly of Linum tenue, followed by the identification of the S-locus using population genomic data. We show that hemizygosity and thrum-specific expression of S-linked genes, including a pistil-expressed candidate gene for style length, are major features of the Linum S-locus. Structural variation is likely instrumental for recombination suppression, and although the non-recombining dominant haplotype has accumulated transposable elements, S-linked genes are not under relaxed purifying selection. Our findings reveal remarkable convergence in the genetic architecture and evolution of independently derived distyly supergenes, provide a counterexample to classic inversion-based supergenes, and shed new light on the origin and maintenance of an iconic floral polymorphism.
European Research Council (ERC) 757451 Swedish Research Council European Commission
Bergstroms foundation Carl Tryggers grant Knut and Alice Wallenberg Foundation as part of the National Bioinformatics Infrastructure Sweden at SciLifeLab
National Genomics Infrastructure (NGI) in Stockholm and Uppsala (Uppsala Genome Center, SNP&SEQ) - Knut and Alice Wallenberg Foundation
Science for Life Laboratory
Swedish Research Council
European Commission 2018-05973
NBIS (National Bioinformatics Infrastructure Sweden)
Databáze: OpenAIRE