Swm1/Apc13 is required for APC/C activity in meiosis. (A) SK1 wild-type cells (Z2827) and swm1Δ/swm1Δ diploid cells (Z3306) homozygous for PDS1-myc18 were transferred to sporulation medium at 30°C at time zero and analyzed by immunoblotting. Cyc, extracts from growing cells. Asterisks mark nonspecific proteins. The percentages of cells with replicated (4C) DNA and of sporulated cells are indicated. (B) Suppression of the sporulation defect by multiple copies of SIC1. SK1 wild-type cells (Z2314) and swm1Δ/swm1Δ (Z4001) and swm1Δ/swm1Δ leu2::SIC1/leu2::SIC1 (Z4420) diploid cells were induced to enter meiosis at 30°C. Top panels, fractions of cells that contain one nucleus (squares) and that have undergone meiosis I (filled circles), meiosis II (open circles), and spore formation (filled triangles). Bottom panels, cellular DNA content.