Molecular Genetics and Genomics

, Volume 275, Issue 6, pp 578–592

Chromosomal and phylogenetic context for conglutin genes in Arachis based on genomic sequence

Authors

  • M. Laura Ramos
    • Department of HorticultureUniversity of Georgia Tifton Campus
  • Geraldine Fleming
    • Department of HorticultureUniversity of Georgia Tifton Campus
  • Ye Chu
    • Department of HorticultureUniversity of Georgia Tifton Campus
  • Yukio Akiyama
    • Department of HorticultureUniversity of Georgia Tifton Campus
  • Maria Gallo
    • Agronomy Department, Plant Molecular and Cellular Biology Program, and The Genetics InstituteUniversity of Florida
    • Department of HorticultureUniversity of Georgia Tifton Campus
Original Paper

DOI: 10.1007/s00438-006-0114-z

Cite this article as:
Ramos, M.L., Fleming, G., Chu, Y. et al. Mol Genet Genomics (2006) 275: 578. doi:10.1007/s00438-006-0114-z

Abstracts

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.

Keywords

Ara h 2Ara h 6ConglutinsPeanut allergensHomeologous genesOrthologous genes

Supplementary material

Copyright information

© Springer-Verlag 2006