Polyploidy, Gene Silencing, and cDNA AFLPs
We are currently investigating the genomic extent of gene silencing in synthetic cotton allopolyploids compared to their diploid parents. Expression levels of homoeologous gene pairs relative to each other in the polyploid is being assayed by a cDNA-AFLP (RNA fingerprinting) approach along with RT-PCR. We are particularly interested in comparing the effects of polyploidy on homoeologous gene expression in floral whorls and leaves to determine if gene silencing is more prevalent in some organs and to infer the genomic extent of silencing that is reciprocal in different organs. Several hundred loci have been screened and over 40 genes have been identified that likely show silencing of one or both homoeologs in the polyploid.