Genes duplicated by polyploidy show unequal contributions to the transcriptome and organ-specific reciprocal silencing

Most eukaryotes have genomes that exhibit high levels of gene redundancy, much of which seems to have arisen from one or more cycles of genome doubling. Polyploidy has been particularly prominent during flowering plant evolution, yielding duplicated genes (homoeologs) whose expression may be retained or lost either as an immediate consequence of polyploidization or on an evolutionary timescale. Expression of 40 homoeologous gene pairs was assayed by cDNA-single-stranded conformation polymorphism in natural (1- to 2-million-yr-old) and synthetic tetraploid cotton (Gossypium) to determine whether homoeologous gene pairs are expressed at equal levels after polyploid formation. Silencing or unequal expression of…

• UD
  U.S. Department of Agriculture
• JC
  Jane Coffin Childs Memorial Fund for Medical Research
• IS
  Iowa State University
• PS
  Plant Sciences Institute, Iowa State University