华中农业大学王茂军等合作取得重要工作进展。他们研究提出，二倍体和四倍体棉花基因组的趋同与分化。相关研究成果2024年10月29日在线发表于《自然—遗传学》杂志上。

据介绍，多倍体是物种形成和演化的重要驱动力；然而，在多倍体和祖先二倍体之间平行选择特定性状的基因组基础尚未得到探索。

研究人员构建了二倍体（A₂）和异源四倍体（AD₁）棉花物种的基于图的泛基因组，这是通过组装50个遗传多样的种质基因组实现的。研究人员绘制了四倍体品种的嵌合基因组图，说明了半野生型向现代品种的基因组贡献。

泛基因组比较确定了二倍体和四倍体棉花之间持续变异的同向和超发散区域，并表明一个持续的序列演化过程可能与两个亚基因组中相反的基因组大小变化有关。

研究人员强调了二倍体基因表达的43%的遗传调控关系，包括多倍体后的序列分歧，并具体描述了六个未被充分探索的收敛遗传位点，这些位点有助于纤维质量的平行选择。

总之，这一研究为生物中理想性状的平行选择背后的遗传调控成分的全基因组解析提供了一个框架。

附：英文原文

Title: Convergence and divergence of diploid and tetraploid cotton genomes

Author: Li, Jianying, Liu, Zhenping, You, Chunyuan, Qi, Zhengyang, You, Jiaqi, Grover, Corrinne E., Long, Yuexuan, Huang, Xianhui, Lu, Sifan, Wang, Yuejin, Zhang, Sainan, Wang, Yawen, Bai, Ruizhe, Zhang, Mengke, Jin, Shuangxia, Nie, Xinhui, Wendel, Jonathan F., Zhang, Xianlong, Wang, Maojun

Issue&Volume: 2024-10-29

Abstract: Polyploidy is an important driving force in speciation and evolution; however, the genomic basis for parallel selection of a particular trait between polyploids and ancestral diploids remains unexplored. Here we construct graph-based pan-genomes for diploid (A2) and allotetraploid (AD1) cotton species, enabled by an assembly of 50 genomes of genetically diverse accessions. We delineate a mosaic genome map of tetraploid cultivars that illustrates genomic contributions from semi-wild forms into modern cultivars. Pan-genome comparisons identify syntenic and hyper-divergent regions of continued variation between diploid and tetraploid cottons, and suggest an ongoing process of sequence evolution potentially linked to the contrasting genome size change in two subgenomes. We highlight 43% of genetic regulatory relationships for gene expression in diploid encompassing sequence divergence after polyploidy, and specifically characterize six underexplored convergent genetic loci contributing to parallel selection of fiber quality. This study offers a framework for pan-genomic dissection of genetic regulatory components underlying parallel selection of desirable traits in organisms.

DOI: 10.1038/s41588-024-01964-8

Source: https://www.nature.com/articles/s41588-024-01964-8