Genomic mosaicism due to homoeologous exchange generates extensive phenotypic diversity in nascent allopolyploids  

作　　者：Ying Wu Fan Lin Yao Zhou Jie Wang Shuai Sun Bin Wang Zhibin Zhang Guo Li Xiuyun Lin Xutong Wang Yue Sun Qianli Dong Chunming Xu Lei Gong Jonathan F.Wendel Zhiwu Zhang Bao Liu 

机构地区：[1]Key Laboratory of Molecular Epigenetics of the Ministry of Education,Northeast Normal University,Changchun 130024,China [2]Department of Crop&Soil Sciences,Washington State University,Pullman,WA 99164,USA [3]Brightseed Inc,San Francisco,CA 94107,USA [4]Department of Ecology,Evolution&Organismal Biology,Iowa State University,Ames,IA 50011,USA

出　　处：《National Science Review》2021年第5期17-31,共15页国家科学评论（英文版）

基　　金：supported by the National Key Research and Development Program of China(2016YFD0102003 to B.L.);the National Natural Science Foundation of China(91131000 to B.L and 31900197 to Y.W.);the China Postdoctoral Science Foundation(2018M631853 and 2019T120228 to Y.W.);the US National Science Foundation(to J.F.W.)。

摘　　要：Allopolyploidy is an important process in plant speciation,yet newly formed allopolyploid species typically suffer from extreme genetic bottlenecks.One escape from this impasse might be homoeologous meiotic pairing,during which homoeologous exchanges(HEs)generate phenotypically variable progeny.However,the immediate genome-wide patterns and resulting phenotypic diversity generated by HEs remain largely unknown.Here,we analyzed the genome composition of 202 phenotyped euploid segmental allopolyploid individuals from the fourth selfed generation following chromosomal doubling of reciprocal F1 hybrids of crosses between rice subspecies,using whole-genome sequencing.We describe rampant occurrence of HEs that,by overcoming incompatibility or conferring superiority of hetero-cytonuclear interactions,generate extensive and individualized genomic mosaicism across the analyzed tetraploids.We show that the resulting homoeolog copy number alteration in tetraploids affects known-function genes and their complex genetic interactions,in the process creating extraordinary phenotypic diversity at the population level following a single initial hybridization.Our results illuminate the immediate genomic landscapes possible in a tetraploid genomic environment,and underscore HE as an important mechanism that fuels rapid phenotypic diversification accompanying the initial stages of allopolyploid evolution.

关 键 词：nascent allopolyploidy homoeologous recombination phenotypic diversity plant evolution GWAS dosage effects EPISTASIS 

分 类 号：Q943[生物学—植物学]