Retrogenes and their contributions to the expansion of lectin genes. (A) Retrogenes identified in soybean and rice genomes. (B) An example showing evolution of a lectin gene Glyma08g46960 by retrotranspositions from another lectin gene Glyma03g00530. The red arrowheads indicate the detected flanking direct repeats in an identified retrogene. The green arrowheads show the start (left) and end (right) positions of an annotated gene. The green boxes indicate the predicted 5'-UTR (left) and 3'-UTR (right) in a retrogene. The blue boxes indicate exons in both retrogenes and their host genes. The white boxes indicate an intron in the parental gene. (C) A retrogene mediated tandem duplication.