Figure 8.

Dosage dependence of homeolog gene expression. Homeolog-specific gene expression was studied either by SSCP (single-stranded conformational polymorphism) analysis (A–C) or by using a methylation-sensitive enzyme (HpaII) on genomic DNA (D). Wheat group 7 nullisomic–tetrasomic (NT) and ditelosomic (DT) lines were used to study effects of homeolog copy number change on expression or methylation pattern. The methylation pattern differences between Chinese spring (CS) and aneuploid stocks of homeologous group 7 chromosomes were studied by gel-blot analysis. The genomic DNA from CS, NT, and DT lines was digested with a methylation-sensitive enzyme and hybridized with BE490149. The genomic fragments identified by physical mapping are depicted as A, B, and D on the left of the autoradiograph. “*” indicates the fragments showing differences in methylation patterns.