GrainGenes Reference Report: SCR-8:5181
Reference
SCR-8:5181
Title
Dynamic Evolution of alpha-Gliadin Prolamin Gene Family in Homeologous Genomes of Hexaploid Wheat
Journal
Scientific Reports
Year
2018
Volume
8
Author
Huo N
[ Show all 10 ]
Abstract
Wheat Gli-2 loci encode complex groups of alpha-gliadin prolamins that are important for breadmaking, but also major triggers of celiac disease (CD). Elucidation of alpha-gliadin evolution provides knowledge to produce wheat with better end-use properties and reduced immunogenic potential. The Gli-2 loci contain a large number of tandemly duplicated genes and highly repetitive DNA, making sequence assembly of their genomic regions challenging. Here, we constructed high-quality sequences spanning the three wheat homeologous alpha-gliadin loci by aligning PacBio-based sequence contigs with BioNano genome maps. A total of 47 alpha-gliadin genes were identified with only 26 encoding intact full-length protein products. Analyses of alpha-gliadin loci and phylogenetic tree reconstruction indicate significant duplications of alpha-gliadin genes in the last ~2.5 million years after the divergence of the A, B and D genomes, supporting its rapid lineage-independent expansion in different Triticeae genomes. We showed that dramatic divergence in expression of alpha-gliadin genes could not be attributed to sequence variations in the promoter regions. The study also provided insights into the evolution of CD epitopes and identified a single indel event in the hexaploid wheat D genome that likely resulted in the generation of the highly toxic 33-mer CD epitope.
External Databases
https://doi.org/10.1038/s41598-018-23570-5
GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture.
GrainGenes Reference Report: SCR-8:5181
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GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture. | |||