Mechanisms of genomic rearrangements and gene expression changes in plant polyploids

✍ Scribed by Z. Jeffrey Chen; Zhongfu Ni

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 380 KB
• Volume: 28
• Category: Article
• ISSN: 0265-9247
• DOI: 10.1002/bies.20374

✦ Synopsis

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.