Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2001
Publication Date: N/A
Interpretive Summary: The wheat high-molecular-weight (HMW) glutenins are a critical component of wheat quality and their genes have been extensively studied. What was not known was any information on the organization of these genes within the wheat gene. We have now sequenced more of the DNA surrounding the HMW- glutenin genes and find evidence of both conservation and divergence of sequence. The longest new sequence gives the first evidence of non- storage-protein genes adjacent to the HMW-glutenin genes, and all the genes have an important control sequence near the beginning of each HWM-glutenin gene. Evidence is also presented on how this gene family is evolving.
Technical Abstract: Extended DNA sequences were characterized for five members of the wheat wheat high-molecular-weight(HMW) glutenin gene family. Analysis revealed more sequence conservation among orthologous regions than between para- logous regions, with differences mainly due to transposition events involving retrotransposons and several miniature-inverted-transposable- elements. Both gypsy-like LTR (long terminal repeat) and non-LTR retrotransposon sequences are represented in the flanking DNAs. One of the MITEs is a novel class, but another MITE is related to the maize Stowaway family and is widely represented in Triticeae ESTs. Flanking DNA of the longest sequence, a 20,425 bp fragment including and surrounding the HMW- glutenin Bx7 gene, showed additional cereal gene-like sequences both immediately 5' and 3' to the HMW-glutenin coding region. The transcrip- tional activities of sequences related to these flanking putative genes and dthe retrotransposon-related regions were indicated by matches to wheat and other Triticeae ESTs. Predictive analysis of matrix-attachment-regions (MARs) of the HMW-glutenin and several alpha-, gamma, and omega-gliadin genes indicate potential MARs immediately flanking all wheat prolamines. Matrix binding activity in the predicted regions was confirmed for two of the HMW-glutenin genes.