Figure 2 : Genome synteny, duplication patterns and evolutionary history of watermelon, cucumber and melon.

From: The draft genome of watermelon (Citrullus lanatus) and resequencing of 20 diverse accessions

Figure 2

(a) Schematic representation of paralogous pairs identified within the watermelon genome (chromosomes w1–w11). Each line represents a syntenic region. Different colors reflect origin from the seven ancestral eudicot chromosome karyotype (A1, A4, A7, A10, A13, A16 and A19). (b) Schematic representation of syntenies among watermelon (chromosomes 1–11), cucumber (chromosomes 1–7) and melon genomes (linkage groups (LG) 1–12). Each line represents a syntenic region. Shared synteny between two of the three species is linked by a light gray line. (c) Evolution of the watermelon genome (w1–w11 at the bottom) from the common eudicot genome ancestors of seven chromosomes (A1, A4, A7, A10, A13, A16 and A19) and the derived paleohexaploid n = 21 (A1–A21) ancestor intermediate. Colored blocks represent the evolution of segments from the 7- or 21-chromosome ancestors to reach the modern watermelon genome structure. The 172 chromosomal fusions and fissions are highlighted with colored arrows. TE, transposable element; WGD, whole-genome duplication.