Fig 1: Fission yeast Rad8 facilitates isochromosome formation.(A) The ChLC chromosome contains an entire region of centromere 3 (cen3) and three genetic markers: LEU2, ura4+, and ade6+. Gross chromosomal rearrangements (GCRs) associated with loss of both ura4+ and ade6+ result in the formation of Leu+ Ura− Ade− cells. The structure and the length of three GCR types: translocation, isochromosome, and truncation are shown. (B) GCR rates of the wild-type, rad8Δ, rad51Δ, and rad8Δ rad51Δ strains (TNF5369, 5549, 5411, and 5644, respectively). Each dot represents an independent experimental value obtained from an independent colony. Black bars indicate medians. Rates relative to that of wild type are shown on the top of each cluster of dots. Statistical analyses between the wild-type and mutant strains, and that between rad51Δ and rad8Δ rad51Δ strains were performed by the two-tailed Mann-Whitney test. **** P < 0.0001. (C) Chromosomal DNAs prepared from the parental (P) and independent GCR clones of rad51Δ and rad8Δ rad51Δ strains were separated by broad- and short-range PFGE (top and bottom rows, respectively). Positions of chr1, chr2, chr3, and ChLC (5.7, 4.6, ~3.5, and 0.5 Mb, respectively) are indicated on the left of broad-range PFGE panels. Sizes of Lambda (λ) ladders (ProMega-Markers, Madison, Wisconsin, G3011) are displayed on the left of short-range PFGE panels. Sample number of truncations are highlighted in red. (D) Rates of each GCR type. Rates relative to those of rad51Δ are indicated. Numerical source data underlying the graphs shown in (B) and (D) are provided respectively in Tables A and B in S1 File.