Fig. 3
From: Transcriptomic analysis links gene expression to unilateral pollen-pistil reproductive barriers
Genome-wide variation in gene expression across five populations of Solanum habrochaites, summarized by their first two principal components. The largest source of variation results from differences in expression between pollen (circles) and styles (unpollinated, squares; pollinated, triangles), on the first PC (horizontal axis). Variation across populations, on the other hand, accumulates on the second PC (vertical axis)