2025-08-26 マックス・プランク研究所(MPG)
<関連情報>
- https://www.mpg.de/25251224/ancient-origins-and-evolutionary-fate-of-sex-chromosomes-in-brown-algae
- https://www.nature.com/articles/s41559-025-02838-w
褐藻類の性染色体の起源と進化経路 Origin and evolutionary trajectories of brown algal sex chromosomes
Josué Barrera-Redondo,Agnieszka P. Lipinska,Pengfei Liu,Erica Dinatale,Guillaume Cossard,Kenny Bogaert,Masakazu Hoshino,Rory J. Craig,Komlan Avia,Goncalo Leiria,Elena Avdievich,Daniel Liesner,Rémy Luthringer,Olivier Godfroy,Svenja Heesch,Zofia Nehr,Loraine Brillet-Guéguen,Akira F. Peters,Galice Hoarau,Gareth Pearson,Jean-Marc Aury,Patrick Wincker,France Denoeud,J. Mark Cock,… Susana M. Coelho
Nature Ecology & Evolution Published:25 August 2025
DOI:https://doi.org/10.1038/s41559-025-02838-w
Abstract
Research on the biology and evolution of sex chromosomes has primarily focused on diploid XX/XY and ZW/ZZ systems. In contrast, the rise, evolution and demise of U/V systems has remained an enigma. Here we analyse genomes of nine brown algal species with different sexual systems to determine the history of their sex determination. U/V sex chromosomes emerged between 450 and 224 million years ago, when a region containing the pivotal male-determinant MIN ceased recombining. Seven ancestral genes within the sex-determining region show remarkable conservation over this vast evolutionary time, although nested inversions caused expansions of the sex locus, independently in each lineage. We evaluate whether these expansions are associated with increased morphological complexity and sexual differentiation, and show that taxonomically restricted genes evolve unexpectedly often in U and V chromosomes. We also investigate two situations in which U/V-linked regions have changed. First, we demonstrate that convergent evolution of two monoicous species occurred by ancestral males acquiring U-specific genes. Second, the Fucus dioecious system involves new sex-determining gene(s), acting upstream of formerly V-specific genes during development. Both situations have led to the demise of U and V chromosomes and erosion of their specific genomic characteristics.
