rec8-29A mutant cells exhibit defects in homologous recombination. (A) Wild-type (A1556), rec8Δ (A18933), and pREC8-SCC1 rec8Δ (A16132) were induced to sporulate. At the indicated times, cells were harvested and assayed by Southern blot for DSBs and recombination products at HIS4/LEU2. (B) Wild-type (A1556), rec8Δ (A18933), rec8-29A (A21618), and rec8-6A (A18936) cells were induced to sporulate. At the indicated times, cells were harvested and assayed by Southern blot for DSBs and recombination products at HIS4/LEU2. (C and D) Blots from A and B were subjected to densitometric analysis to quantitate the intensity of the bands representing the upper recombinant band. Values were normalized to the “Mom” parental band for each strain and each time point. (E) Meiotic progression of the strains assayed for recombination shown in A and B. Wild-type (A1556, ◇), rec8Δ (A18933, ■), pREC8-SCC1 rec8Δ (A16132, ○), rec8-29A (A21618, ·), and rec8-6A (A18936, ▴) cells were induced to sporulate. At the indicated times, samples were taken and subjected to α-tubulin immunofluorescence to determine the percentage of cells with unassembled spindles. n = 200 cells counted per strain per time point.