Chromosome III map distances in SUMO-diminished strains.

Strains carrying an smt3 deletion allele give predominantly 2-spore viables, thus random spore analysis was used to calculate map distances and standard errors between three intervals on chromosome III in all SUMO-diminished and control backgrounds (see Methods). Cen3 was marked using a hygromycin resistance cassette and RAD18 was marked using the ADE2 gene. Standard error (S.E.) values were calculated according to the formula: 100(√(r/t)(1-r/t)/t), where r = number of recombinant colonies and t = total number of colonies counted. Additionally (middle section of the table), map distances were calculated using tetrad analysis as per Perkins [56]. Tetrad analysis to generate genetic distances and standard error (S.E.) values using tetrad data were calculated using the Stahl lab online tools: http://molbio.uoregon.edu/~fstahl/. For 175 tetrads in K189 cells, two (3∶1) segregation events were evident at the HIS4 locus, one event occurred at the MAT locus and four events (all 3∶1 ADE2+:ade2) occurred at RAD18. For 192 tetrads from K188 cells, five (3∶1) segregation events were evident at HIS4, two events occurred at MAT, and nine events (seven (3∶1) and two (1∶3) ADE2+:ade2 events) occurred at RAD18. Interference values (lower section of table) were calculated using tetrad analysis data. Interference was measured by calculating the ratio of Non Parental Ditype tetrads (NPDs) observed over the NPDs expected (values less than one reflect positive interference). NPDs expected for each interval were calculated using the fraction of tetratypes (TT) observed in each dataset according to the formula: NPDexp = 1/2(1-fTT-[1-3fTT/2]2/3 (where fTT = fraction of tetratypes) [59]. Numbers in the “Prob.” column represent the two-sided P value (Fisher's Exact Test) that describes the probability that the difference between observed and expected NPD proportions are due to chance. Prob. values in bold indicate statistical significance.