Phenotypes of bqt3Δ and -4Δ cells. (A) Loss of telomere clustering in bqt3Δ and -4Δ cells. Cells expressing Taz1-GFP (green) and Sad1-mRFP (red) were observed after the induction of meiosis. The image at each wavelength is a projection of selected optical section images. The strains used are CRLs63 (h⁹⁰ bqt3Δ::ura4⁺, taz1Δ::ura4⁺, lys1::taz1-GFP, sad1-mCherry::kan) and CRLp85 (h⁹⁰ bqt4Δ::ura4⁺, taz1Δ::ura4⁺, lys1::taz1-GFP, sad1-mCherry::kan). (B) Spore formation and spore viability. Normal four-spore formation percentage = 100 x (number of asci containing four normal spores)/(number of randomly selected asci dissected). Spore viability percentage = 100 × (number of viable spores)/(4 × [number of asci dissected randomly]). The strains used are CRLs95 (wild type [WT]; 76 asci), CRLm03 (bqt2Δ::ura4⁺; 90 asci), CRLs57 (bqt3Δ::ura4⁺; 77 asci), and CRLp86 (bqt4Δ::ura4⁺; 93 asci). (C) Phase contrast image of asci of the bqt4Δ strain with defects in spore formation. (D) Random spore analysis and genetic linkage. Genetic distance according to Haldane's formula: d = −50 × ln(1 − 2R/[R + P]), where R is the number of recombinants and P is the number of colonies with parental genotype. Bars, 10 µm.