Phenotypic analyses and trait mapping using 36 RTG diploid strains.

<p>(A) Semi-quantitative measure of growth rate by spot assay (<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005781#sec015" target="_blank">Materials and Methods</a>) for the parental S288c and SK1 haploids, the hybrid S288c/SK1 diploid and the RTG2-S, RTG9-M and RTG9-D diploid cells which are representative of the degree of growth variation observed among the 36 RTG strains. Control: standard medium; Arsenite: standard medium + NaAsO2 1.5mM. (B) LOD (logarithm of odds) score values along the 16 chromosomes for leucine auxotrophy, a monogenic binary trait. A region of 10kb [chr. III: ~65-76kb] shows a significant association with leucine auxotrophy and includes the expected causal <i>HIS4-LEU2</i> locus [chr. III: ~66-68kb]. (C) LOD score values along the 16 chromosomes for methionine auxotrophy, a monogenic binary trait. A region of 265kb [chr. XII: ~627-892kb] shows a significant association with methionine auxotrophy and includes the causal <i>MET15</i> locus [chr. XII: ~733-734kb]. (D) LOD score values along the 16 chromosomes for histidine auxotrophy, a digenic binary trait. A region of 219kb [chr. XV: ~690-909kb] shows a significant association with histidine auxotrophy and includes one causal locus <i>HIS3</i> [chr. XV: ~722 -723kb]. However, no significant association is found with the second causal locus <i>HIS4-LEU2</i> [chr. III: ~66-68kb]. (E) LOD score values along the 16 chromosomes for arsenite resistance. Coordinates of the unique significant linkage interval: chr. XVI: ~819–925 kb. The zoom-in outlines the LOD peak value towards the end of chromosome XVI. The ARR (ARsenicals Resistance) cluster (black arrow head, coordinates chr. XVI: ~938-941kb) is a cluster of three genes, <i>ARR1</i>, <i>ARR2</i> and <i>ARR3</i>, located distal to our ultimate genotyped SNP position of this chromosomal arm (chr. XVI: 928,226bp). The ARR cluster of genes is present in the S288c strain background but absent in SK1.