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.携带smt3缺失等位基因的菌株主要产生2孢子存活型四分体，因此本研究采用随机孢子分析（random spore analysis），对所有小泛素样修饰蛋白（SUMO）功能减弱的背景与对照背景下三号染色体（chromosome III）上三个区间的遗传图距（map distances）及标准误（standard errors）进行计算（详见方法部分）。本研究使用潮霉素抗性盒（hygromycin resistance cassette）标记Cen3，使用ADE2基因（ADE2 gene）标记RAD18。标准误（S.E.）按照如下公式计算：100(√(r/t)(1-r/t)/t)，其中r为重组菌落数，t为统计的总菌落数。此外（表格中部），本研究参照Perkins[56]的方法采用四分体分析（tetrad analysis）计算遗传图距。基于四分体数据生成遗传距离与标准误（S.E.）的四分体分析，通过Stahl实验室在线工具（http://molbio.uoregon.edu/~fstahl/）完成计算。针对K189细胞的175个四分体，HIS4基因座（HIS4 locus）上存在2次（3∶1）分离事件，MAT基因座（MAT locus）上存在1次分离事件，RAD18基因上存在4次（均为3∶1 ADE2+:ade2）分离事件。针对K188细胞的192个四分体，HIS4基因座上存在5次（3∶1）分离事件，MAT基因座上存在2次分离事件，RAD18基因上存在9次分离事件（其中7次为(3∶1)、2次为(1∶3) ADE2+:ade2事件）。干涉值（表格下部）通过四分体分析数据计算得到。干涉值通过观测到的非亲二型四分体（Non Parental Ditype tetrads, NPDs）与预期NPDs的比值进行衡量（比值小于1表示存在正干涉）。每个区间的预期NPD数按照如下公式，基于各数据集观测到的四型四分体（tetratypes, TT）占比计算得到：NPDexp = 1/2(1-fTT-[1-3fTT/2]^2/3，其中fTT为四型四分体占比[59]。“Prob.”列中的数值为双侧P值（费希尔精确检验（Fisher's Exact Test）），用于描述观测与预期NPD比例间的差异由随机误差导致的概率。加粗的Prob.值表示具有统计学显著性。