title: Genome-Wide Gene Expressions Respond Differently to A-subgenome Origins inBrassica napusSynthetic Hybrids and Natural Allotetraploid.
abstract: The young allotetraploidBrassica napus(2n= 38, AACC) is one of models to study genomic responses to allopolyploidization. The extraction of AA component from naturalB. napusand then restitution of progenitorB. rapashould provide a unique opportunity to reveal the genome interplay for gene expressions during the evolution. Herein,B. napushybrids (2n= 19, AC) between the extracted and extantB. rapa(2n= 20, AA) and the sameB. oleraceagenotype (2n= 18, CC) were studied by RNA-seq and compared with naturalB. napusdonor, to reveal the gene expression changes from hybridization and domestication and the effects of A genome with different origins. Upon the initial merger of two diploid genomes, additive gene expression was prevalent in these two hybrids, for non-additively expressed genes only represented a small portion of total expressed genes. A high proportion of genes exhibited expression level dominance, with no preference to either of the parental genomes. Comparison of homoeolog expressions also showed no bias toward any genomes and the parental expression patterns were often maintained in the hybrids and natural allotetraploids. Although, the overall patterns of gene expression were highly conserved between two hybrids, the extractedB. raparesponded less and appeared more compatible for hybridization than the extantB. rapa. Our results suggested that expression level dominance and homoeolog expressions bias were balanced at the initial stage of genome merger, and such balance were largely maintained during the domestication ofB. napus, despite the increased extent over time.
authors: National Key Lab of Crop Genetic Improvement, National Center of Crop Molecular Breeding Technology, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural UniversityWuhan, China; Key Laboratory of Ecological Remediation and Safe Utilization of Heavy Metal-Polluted Soils, College of Life Science, Hunan University of Science and TechnologyXiangtan, China.
authors: Dawei
authors: D
authors: Zhang
authors: National Key Lab of Crop Genetic Improvement, National Center of Crop Molecular Breeding Technology, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors: Qi
authors: Q
authors: Pan
authors: National Key Lab of Crop Genetic Improvement, National Center of Crop Molecular Breeding Technology, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors: Chen
authors: C
authors: Tan
authors: National Key Lab of Crop Genetic Improvement, National Center of Crop Molecular Breeding Technology, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors: Bin
authors: B
authors: Zhu
authors: National Key Lab of Crop Genetic Improvement, National Center of Crop Molecular Breeding Technology, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors: Xianhong
authors: X
authors: Ge
authors: College of Chemistry and Life Science, Hubei University of Education Wuhan, China.
authors: Yujiao
authors: Y
authors: Shao
authors: National Key Lab of Crop Genetic Improvement, National Center of Crop Molecular Breeding Technology, National Center of Oil Crop Improvement, College of Plant Science and Technology, Huazhong Agricultural University Wuhan, China.
authors: Zaiyun
authors: Z
authors: Li
keywords: Brassica napus; RNA-Seq; additive gene expression; allopolyploidization; expression level dominance