西南大学徐洛浩课题组的研究显示，染色体融合触发自多倍体基因组的再倍化。2026年4月22日出版的《自然》杂志发表了这项成果。

然而，研究组仍然不了解WGD6创造的重复基因（同源物）的出现和分化所需要的再倍化的第一步。因此，自多倍体产生的功能潜能如何在进化过程中实现仍不清楚。雪鲤（裂腹鲤）具有最近的WGDs历史，并进化出了高海拔适应性，这使得这些鱼成为研究再倍化早期阶段和后果的特别合适的系统。

所有雪鲤属的基因组数据揭示了它们的自多倍体起源，包括四倍体、六倍体和一个二十倍体（20n）。该课题组研究人员展示了来自不同谱系的两种雪鲤（裂腹鲤和曲线裂腹鲤）的单倍型解析基因组，揭示了单一祖先的自四倍体事件。比较基因组学、减数分裂配对和等位基因组成分析表明，不平衡的染色体是四体遗传向二体遗传转变的原因，产生了包含二倍体全染色体对的基因组区域，而未重排的染色体则保留了四倍体。这项研究表明，这一机制启动了再倍化，并记录了其早期染色体和基因组的后果。它从染色体融合位点开始，向外扩展到染色体臂，这一过程在物种形成后仍然不完整，导致在高度合染色体上的祖先和谱系特异性同源分化的混合。

据介绍，所有脊椎动物的祖先都被认为经历了自多倍体全基因组复制（WGD），使进化多样化的遗传原料加倍。

附：英文原文

Title: Chromosomal fusions trigger rediploidization of autopolyploid genomes

Author: Xie, Chuanshuai, Ma, Zitu, Zhou, Chaowei, Ma, Kexin, Wang, Haoyu, Wu, Jiahong, Zhou, Yan, Lu, Yongrui, Ji, Da, Gu, Xuedie, Gao, He, Li, Junting, Fu, Suxing, Li, Weiqiang, Han, Zhaofang, Xiao, Shijun, Liu, Fei, Zeng, Benhe, Chen, Shengao, Niu, Jiangong, Zhang, Tao, Shen, Jian, Liu, Chunna, Luo, Jing, Macqueen, Daniel J., Meyer, Axel, Liu, Haiping, Xu, Luohao

Issue&Volume: 2026-04-22

Abstract: The ancestor of all vertebrates is thought to have undergone autopolyploid whole-genome duplication (WGD)1,2, doubling the genetic raw material for evolutionary diversification3,4,5. However, we still do not understand the first steps of rediploidization that followed, required for the emergence and divergence of duplicated genes (ohnologues) created by WGD6,7. Consequently, how the functional potential created by autopolyploidy becomes realized during evolution remains unclear. Snow carps (Schizothoracine) have a history of recent WGDs and evolved high-altitude adaptations8,9,10, 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.

DOI: 10.1038/s41586-026-10439-1

Source: https://www.nature.com/articles/s41586-026-10439-1