Decreased pericentromeric crossovers in <i>met1–3</i>.

<p>(A) Physical map of chromosome 3 with overlaid genes/Mb (green), cM/Mb (red) and DNA methylation (blue) plots. The dotted, horizontal red line indicates the cM/Mb weighted mean. Outer vertical black lines indicate the position of FTL transgene insertions that define <i>CEN3</i>. Inner vertical black lines indicate the position of centromeric markers analyzed in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002844#pgen-1002844-g002" target="_blank">Figure 2</a>. The vertical magenta line indicates the centromere. (B) Chromosomes heterozygous for <i>trans-</i>linked <i>FTL332</i> (eYFP) and <i>FTL2536</i> (DsRed) transgenes, which flank the centromere (black circle) segregating through meiosis-I and –II in the absence (left) or presence (right) of a CO within <i>CEN3</i>. (C) Fluorescence micrographs of <i>qrt1–2</i> pollen showing patterns of inheritance associated with (tetratype) or without (parental ditype) a CO within <i>CEN3</i>. BF shows bight field illumination and R and G indicate red and green UV fluorescence. (D) <i>CEN3</i> genetic map lengths for naïve wild type (Col), <i>MET1</i>, <i>met1–3^+/−</i>, <i>met1–3^−/−</i> segregants and self-fertilized <i>met1–3^−/−</i> measured by <i>qrt1–2^−/−</i> tetrad counting. (E) Southern blotting and hybridization analysis of <i>CEN180</i> following digestion of genomic DNA using DNA methylation sensitive <i>HpaII</i>. DNA was prepared from <i>CEN3 qrt1–2^−/−</i> individuals whose measured genetic distance in cM is indicated above the blot in blue in addition to their <i>met1–3</i> genotype. See also <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002844#pgen.1002844.s005" target="_blank">Table S3</a>.