State Key Laboratory for Conservation and Utilization of Bio-resource and School of Life Sciences, Yunnan University, Kunming, 650091 Yunnan, China.
State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223 Yunnan, China.
Sci Adv. 2020 May 27;6(22):eaaz7677. doi: 10.1126/sciadv.aaz7677. eCollection 2020 May.
A persistent enigma is the rarity of polyploidy in animals, compared to its prevalence in plants. Although animal polyploids are thought to experience deleterious genomic chaos during initial polyploidization and subsequent rediploidization processes, this hypothesis has not been tested. We provide an improved reference-quality de novo genome for allotetraploid goldfish whose origin dates to ~15 million years ago. Comprehensive analyses identify changes in subgenomic evolution from asymmetrical oscillation in goldfish and common carp to diverse stabilization and balanced gene expression during continuous rediploidization. The homoeologs are coexpressed in most pathways, and their expression dominance shifts temporally during embryogenesis. Homoeolog expression correlates negatively with alternation of DNA methylation. The results show that allotetraploid cyprinids have a unique strategy for balancing subgenomic stabilization and diversification. Rediploidization process in these fishes provides intriguing insights into genome evolution and function in allopolyploid vertebrates.
一个持久的谜是多倍体在动物中的罕见性，与在植物中的普遍性相比。尽管多倍体动物被认为在最初的多倍化和随后的重倍化过程中经历有害的基因组混乱，但这一假设尚未得到检验。我们为大约 1500 万年前起源的异源四倍体金鱼提供了一个改进的参考质量从头基因组。综合分析确定了亚基因组进化的变化，从金鱼和鲤鱼的不对称振荡到连续重倍化过程中多样化的稳定和平衡基因表达。同系物在大多数途径中共同表达，它们的表达优势在胚胎发生过程中随时间变化。同系物的表达与 DNA 甲基化的交替呈负相关。研究结果表明，异源四倍体鲤科鱼类有一种独特的策略来平衡亚基因组的稳定和多样化。这些鱼类的重倍化过程为研究多倍体脊椎动物的基因组进化和功能提供了有趣的见解。
