Chromosomal fusions trigger rediploidization of autopolyploid genomes
, making these fish a particularly suitable system to study the early stages and consequences of rediploidization. Here genomic data from all snow carp genera reveal their autopolyploid origin, including tetraploids, hexaploids and one icosaploid (20n). We present haplotype-resolved genomes for two snow carp species (Schizopygopsis younghusbandi and Schizothorax curvilabiatus) from divergent lineages, revealing a single ancestral autotetraploidy event. Comparative genomic, meiotic pairing and allele composition analyses indicate that unbalanced chromosome fusions were responsible for the transition from tetrasomic to disomic inheritance, creating genomic regions harbouring diploid ohnologue pairs, with non-rearranged chromosomes remaining tetraploid. This study suggests that this mechanism initiated rediploidization and documents its early chromosomal and genomic consequences. It starts at chromosome fusion sites and expands outwards towards chromosomal arms, a process that remained incomplete post-speciation, leading to a mixture of ancestral and lineage-specific ohnologue divergence on highly syntenic chromosomes.
Authors
- Shengao Chen (ORCID: https://orcid.org/0000-0003-0716-8511)
- Suxing Fu (ORCID: https://orcid.org/0009-0001-0562-1469)
- Xuedie Gu
- Chuanshuai Xie (ORCID: https://orcid.org/0000-0001-7239-2347)
- Jiangong Niu (ORCID: https://orcid.org/0000-0001-5643-5490)
- Axel Meyer (ORCID: https://orcid.org/0000-0002-0888-8193)
- Luohao Xu (ORCID: https://orcid.org/0000-0002-3714-8047)
- Yongrui Lu
- Chunna Liu
- Daniel J. Macqueen (ORCID: https://orcid.org/0000-0001-8050-7722)
- Benhe Zeng (ORCID: https://orcid.org/0000-0002-2625-4928)
- Jiahong Wu (ORCID: https://orcid.org/0000-0002-5309-7948)
- Zhaofang Han (ORCID: https://orcid.org/0000-0002-8465-0961)
- Shijun Xiao (ORCID: https://orcid.org/0000-0001-5855-0812)
- Haiping Liu (ORCID: https://orcid.org/0000-0002-6280-0850)
- Kexin Ma (ORCID: https://orcid.org/0000-0002-9930-0104)
- Junting Li (ORCID: https://orcid.org/0000-0001-6889-0968)
- Fei Liu
- Zitu Ma
- Jing Luo
- Jian Shen
- Haoyu Wang (ORCID: https://orcid.org/0000-0003-0505-0237)
- Tao Zhang (ORCID: https://orcid.org/0000-0003-2308-094X)
- Da Ji (ORCID: https://orcid.org/0009-0003-2184-1052)
- He Gao
- Yan Zhou
- Chaowei Zhou
- Weiqiang Li
Institutions
- Roslin Institute (GB)
- Southwest University (CN)
- Yunnan University (CN)
- University of Konstanz (DE)
- Tarim University (CN)
- China Institute of Water Resources and Hydropower Research (CN)
- South China Sea Institute Of Oceanology (CN)
- Jilin Agricultural Science and Technology University (CN)
- Research Institute of Animal Husbandry (MN)
- Jilin Agricultural University (CN)
- Xinjiang Uygur Autonomous Region Education Department (CN)
- University of Edinburgh (GB)
Publication Details
- Journal
- Nature
- Published
- 2026-04-22
- DOI
- https://doi.org/10.1038/s41586-026-10439-1
- Primary Topic
- Chromosomal and Genetic Variations
- Type
- article
- Field-Weighted Citation Impact
- 0.00