Mechanisms of genomic rearrangements and gene expression changes in plant polyploids.
Polyploidy is produced by multiplication of a single genome (autopolyploid) or combination of two or more divergent genomes (allopolyploid). The available data obtained from the study of synthetic (newly created or human-made) plant allopolyploids have documented dynamic and stochastic changes in genomic organization and gene expression, including sequence elimination, inter-chromosomal exchanges, cytosine methylation, gene repression, novel activation, genetic dominance, subfunctionalization and transposon activation. The underlying mechanisms for these alterations are poorly understood. To promote a better understanding of genomic and gene expression changes in polyploidy, we briefly review origins and forms of polyploidy and summarize what has been learned from genome-wide gene expression analyses in newly synthesized auto-and allopolyploids. We show transcriptome divergence between the progenitors and in the newly formed allopolyploids. We propose models for transcriptional regulation, chromatin modification and RNA-mediated pathways in establishing locus-specific expression of orthologous and homoeologous genes during allopolyploid formation and evolution.
Chen
Z Jeffrey
ZJ
Molecular Cell and Developmental Biology, University of Texas, Austin, 78714, USA. zjchen@mail.utexas.edu
Ni
Zhongfu
Z
D032461:Chromosomes, Plant; D015870:Gene Expression; D005786:Gene Expression Regulation; D015321:Gene Rearrangement; D006801:Humans; D010944:Plants / Q000235:genetics* / Q000378:metabolism; D011123:Polyploidy