About the Cover

About the Cover
A novel color segregation and colony morphology phenotype in the yeast Saccharomyces cerevisiae. The red parental strain (top left) carries an ade2 mutation resulting from insertion of a short repetitive minisatellite sequence, the ade2-min3 allele. Loss of a minisatellite repeat in this tract restores both the reading frame of the ADE2 gene and the white color to the cells containing the tract alteration. Loss of the ZRT1 gene, which encodes a high-affinity zinc transporter, leads to elevated minisatellite instability only during stationary phase, resulting in white microcolonies or papillae (called “blebs” in this context) growing on the red colonies (ade2-min3 zrt1; bottom row, left and right). Deletion of the zinc-dependent RAD50 gene, which encodes a central factor in recombination and double-strand break repair, partially suppresses the blebbing phenotype (ade2-min3 Δzrt1 Δrad50; top right). For further details, see KELLY et al. (pp. 2469–2479).