Defective telomere clustering and reduced spore viability and recombination in the mto1Δ mutant and defective telomere interaction of Alp4 and microtubules in the mto1Δ, kms1Δ, and dhc1Δ dlc1Δ zygotes. (A) Telomere clustering defects in mto1Δ zygotes. (B) Reduced spore viability and meiotic recombination in the mto1Δ mutant. n, number of spores or tetrads that were examined. Graphs of gene conversion show mean ade⁺ frequencies. Error bars indicate SEM (n = 3). (C) Sad1 and telomere localization and their colocalization frequency. (D) Alp4 and Sad1 localization and their colocalization frequency. Arrowheads indicate Alp4-free (white) and -diminished (magenta) Sad1 dots. (E) Colocalization frequency of Mto1 and Sad1. (F) Microtubule organization (Mt) and Sad1 location (magenta arrowheads). Green arrowheads, SPB-originated MTOCs. An obvious MTOC was not observed in the mto1Δ mutant. White lines in images indicate cell shapes. Wt, wild type.