Figure 1. Pollen-tube pathway transformation technique. (A) Cross-section of a fertilized cotton flower (not to scale) with a pollen tube connecting the pollen grain and an ovule. (B) The petals and top of the pistil are removed from the fertilized flower to expose the ovary. Exogenous DNA containing a transgene(s) is injected into the exposed ovary, where the DNA travels down the pollen tube to the fertilized ovule.