Figure 6

Fine mapping of eQTL regulating ABA 8'-hydroxylase. A Microarray expression data revealed greater expression of the target gene ABA 8'-hydroxylase. The target gene is present in both parental backgrounds but is much more strongly expressed under control of a B73 derived allele of the trans-regulator glutamine amidotransferase. Multiple splice variants are amplified from the pseudogene cDNA. Sequence analysis of variants shows that only the smallest band is able to hybridize to the microarray probe, asterisk. Among parental controls, the B73 inbred average expression shows a 9-fold greater expression of the pseudogene as compared the Mo17 inbred. An F1 hybrid shows mid-level expression regulation of the relevant band, asterisk, as well as several others. B Example phenotypes/genotypes found within the IBM2 Syn10 population and controls. Phenotypes are considered "high" or "low" depending on the relative ABA 8'hydroxylase target gene expression levels. B73 alleles of the eQTL allow for high expression of the target as compared to Mo17 alleles; B73 derived allele = green, Mo17 derived allele = blue. Fine mapping of the IBM2 Syn10 population using molecular markers (M1-M6) identified a very small region at the 3' end of the gene as being the responsible element that determines the expression of the target. C BACs within eQTL interval with public markers (IDP markers; red) and designed mapping markers M1-M6 (teal) spanning the region (not drawn to scale). IDP3798 and two mapping markers are located within the glutamine amidotransferase gene.