The <i>mop1-1</i> mutation prevents pBΔ-induced paramutation of <i>B-I</i>.

aFour families, representing the progeny of four individual mop1-1 homozygotes, were examined for each transgenic event. The families were derived from outcrossing homozygous mop1-1 plants carrying B-I and a paramutagenic b1 repeat transgene to b-N plants (details of the crosses performed are shown in Figure S5). The number of purple plants is shown before the slash, with the total number of plants scored indicated after the slash. The frequency of dark plants is shown in parenthesis.