“…However, recent evidence indicates that there is a preferential retention of transcription factors and signal transduction components as duplicates from the most recent respective events of polyploidization and diploidization in both Arabidopsis and rice (8)(9)(10)28). Indeed, there is evidence of purifying selection for the genes that are preferentially retained (10). By comparison, studies of the types of genes present in segmental duplications, which increase the copy number of only a small portion of the genome, provide a complementary picture, namely, a relative dearth of transcription factors and signal transduction components (30).…”