A total of 205 ABC genes were involved in recent duplications, with 25% (ranging from 17%to31%1%) of annotated transporters in the seven species (Table 2).> -wrap-foot> aA block of duplication was defined if more than one gene was involved in the duplication.
A block of duplications was defined if more than one gene was involved in the duplication.
The "unplaced" chromosome (ChrUnAll) in Btau_4.0 showed a marked enrichment for blocks of segmental duplication, with almost half (45.2/94.4 Mb) of the duplications assigned to this category.
We found a strong correspondence between Jiang et al.'s clades and connected subgraphs in our DAG; five of the nine connected components with at least four blocks were comprised of duplication blocks belonging to a single clade and seven of the nine components were comprised of blocks belonging to no more than two clades.
In determining whether the CCSD or PM3 genes were located in any of the known blocks of genome duplication, we found that the high degree of sequence similarity between the SOGG3 genes ZmSUN3 and ZmSUN4 suggests they arose as part of a gene-duplication event that is known to have resulted in many closely related gene pairs in maize [ 56, 58].
They are flanked by large blocks of segmental duplications and carry presumably rapidly evolving genes.
This has corroborated the idea of a complex mosaic structure of supernumerary chromosomes, representing autonomous blocks of segmental duplications and heterochromatin [ 18].
Data from one study show that many large inversions, surrounded by blocks of segmental duplications, have arisen on more than one haplotype background [ 48].
However, it is very likely that smaller inversions that are not flanked by blocks of segmental duplications will have arisen only once and will therefore be in LD with surrounding SNPs.
Still, it is notable that three of the six Gm Hsp20 genes that are responsive to M. javanica and H. glycines infection (Gm Hsp17.4A, Gm Hsp17.9B [ 6] and Gm Hsp17.6B [ 7]) are organized in blocks of segmental duplications in the genome.
We refer to other noncoding blocks within 5 kb of duplication peptides as nonchained DA blocks (see, e.g., fig. 1).
