Figure 6

Model explaining the influence of additively expressed, linear with heterosis-correlated genes on heterosis. In the boxes the expression levels of three hypothetical genes in two parental inbred lines (Parent 1 and 2) and their hybrid progeny (Hybrid) are shown by triangles (gene 1), circles (gene 2) and squares (gene 3). The expression of all three genes either show a positive (genes 1 and 3) or a negative (gene 2) linear correlation with heterosis illustrated by a consistent transition from white to black; white is representing a more favorable gene expression regarding the phenotype. Additive expression levels in the hybrid are compensating for detrimental expression in one or the other parent. The cumulative effect of overall more balanced gene expression in hybrids contributes to heterosis.