Chromosomal and phylogenetic context for conglutin genes in Arachis based on genomic sequence.
Comparative genomic and cDNA sequence analysis of ara h 2, a major peanut allergen, and a related conglutin ara h 6 were performed in Arachis hypogaea L. and its putative progenitors, Arachis duranensis and Arachis ipaensis. The complete identity between sequences encoding Ara h 2 isoforms demonstrated that these are homeologous genes and represent orthologs from diploid ancestors. Three copies of ara h 6 were identified in A. hypogaea, one of them located in the A-genome and the other two in the B-genome. Expression analysis showed higher levels of ara h 2 transcripts compared with ara h 6. Dual-labeled genomic in situ hybridization permitted identification of two subgenomes, each of which contained one pair of ara h 2-ara h 6 signals localized by fluorescence in situ hybridization. Characterization of genomic clones showed close genetic linkage between Ara h 2.02 and one copy of ara h 6 in the B-genome. The physical linkage may have arisen by tandem duplication and divergence of an ancestral gene. A gene duplication event specific to the B-genome progenitor has resulted in ara h 6 paralogs. These data provide further evidence for progenitor relationships and genomic organization of the conglutin gene family in the genus Arachis and could contribute to the development of a hypoallergenic peanut.
Ramos
M Laura
ML
Department of Horticulture, University of Georgia Tifton Campus, Tifton, GA, 31793, USA.
Fleming
Geraldine
G
Chu
Ye
Y
Akiyama
Yukio
Y
Gallo
Maria
M
Ozias-Akins
Peggy
P
D010367:Arachis / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D032461:Chromosomes, Plant; D018744:DNA, Plant; D018745:Genome, Plant; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D018744:DNA, Plant; D010940:Plant Proteins