cis versus trans effects

Hughes KA, Ayroles JF, Reedy MM. Drnevich JM, Rowe KC, Ruedi EA, Caceres CE & Paige KN 2006 Segregating variation in the transcriptome: cis regulation and additivity of effects. Genetics 173:1347-1355.

• cis and trans effects on gene expression are numerically about equal
• cis effects account for more genetic variation than do trans effects

• additivity or intermediate dominance (0 < |d / a| < .5): 1128 transcripts
• intermediate-to-complete dominance (.5 < |d / a| < 1): 330
• overdominance (|d / a| > 1): 131

• trans effects may be more typical of between- than of within-population variation
• since selection acting within populations may strictly limit variation in trans-acting genes with multiple down-stream effects