Figure 2. Gene conversion test loci.

(A) After pre-meiotic DNA synthesis, meiocytes in plants that are heterozygous for fluorescent and non-fluorescent alleles of the FTL transgene cassettes will have two copies of each allele. (B) Following meiosis those alleles will segregate in pollen tetrads. If no gene conversion occurs at the test locus the fluorescent signal will segregate in a 2∶2 ratio (asterisk). In contrast, gene conversion will result in a 3∶1 segregation ratio (arrow). (C) A monochrome image with the exposure and contrast globally increased using Photoshop enables easier visualization of the non-fluorescent pollen grains in the tetrads.