wheat expression level polymorphism study 39 genotypes 2 biological reps

The use of statistical tools established for the genetic analysis of quantitative traits can be applied to gene expression data. Quantitative trait loci (QTL) analysis can associate expression of genes or groups of genes with particular genomic regions and thereby identify regions that play a role in the regulation of gene expression. A segregating population of 41 doubled haploid (DH) lines from the hard red spring wheat cross RL4452 x AC Domain was used. This population had previously been mapped with microsatellites and includes a full QTL analysis for agronomic and seed quality traits. Expression analysis from 5 day post anthesis developing seed was conducted on 39 of the 41 DH lines using the Affymetrix wheat array. Expression analysis of developing seeds from field grown material identified 1,327 sequences represented by Affymetrix probe sets whose expression varied significantly between genotypes of the population. A sub-set of 378 transcripts were identified that each mapped to a single chromosome interval illustrating that major expression QTLs can be found in wheat. Genomic regions corresponding to multiple expression QTLs were identified that were coincident with previous identified seed quality trait QTL. These regions may be important regulatory regions governing economically important traits. Comparison of expression mapping data with physical mapping for a sub-set of sequences showed that both cis and trans acting expression QTLs were present.

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Jordan MC, Somers DJ, Banks TW