Figure 10.

Duplication of 830 bp of matA 5′ flanking sequences at the resident matA locus interferes with the expression and molecular function of the matA transgene. Structure of the complemented endogenous matA(0) locus and associated phenotype are shown. Bars represent matA with flanking regions and pyrG/pyrG89 gene. Solid line represents vector sequence of pWP3; dashed line represents deleted 5′ flanking sequences from −1001 to −171. Shaded box represents silencer element. (A) Integration of the pWP3 plasmid via 3′ homology introduces a duplication of 830 bp of 5′ flanking sequences at the resident matA locus and interferes with fertility. (B) Integration of the pWP3 (∆830 bp), via 3′ homology at the resident matA locus results in wild-type fertility.