Sequence level analysis of recently duplicated regions in soybean [Glycine max (L.) Merr.] genome.
A single recessive gene, rxp, on linkage group (LG) D2 controls bacterial leaf-pustule resistance in soybean. We identified two homoeologous contigs (GmA and GmA') composed of five bacterial artificial chromosomes (BACs) during the selection of BAC clones around Rxp region. With the recombinant inbred line population from the cross of Pureunkong and Jinpumkong 2, single-nucleotide polymorphism and simple sequence repeat marker genotyping were able to locate GmA' on LG A1. On the basis of information in the Soybean Breeders Toolbox and our results, parts of LG A1 and LG D2 share duplicated regions. Alignment and annotation revealed that many homoeologous regions contained kinases and proteins related to signal transduction pathway. Interestingly, inserted sequences from GmA and GmA' had homology with transposase and integrase. Estimation of evolutionary events revealed that speciation of soybean from Medicago and the recent divergence of two soybean homoeologous regions occurred at 60 and 12 million years ago, respectively. Distribution of synonymous substitution patterns, K(s), yielded a first secondary peak (mode K(s) = 0.10-0.15) followed by two smaller bulges were displayed between soybean homologous regions. Thus, diploidized paleopolyploidy of soybean genome was again supported by our study.
Van
Kyujung
K
Department of Plant Science, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, Seoul 151-921, South Korea.
Kim
Dong Hyun
DH
Cai
Chun Mei
CM
Kim
Moon Young
MY
Shin
Jin Hee
JH
Graham
Michelle A
MA
Shoemaker
Randy C
RC
Choi
Beom-Soon
BS
Yang
Tae-Jin
TJ
Lee
Suk-Ha
SH
D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D032461:Chromosomes, Plant; D019143:Evolution, Molecular; D020440:Gene Duplication; D018745:Genome, Plant; D008969:Molecular Sequence Data; D011123:Polyploidy; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000235:genetics*