A nematode-specific gene underlies bleomycin-response variation in Caenorhabditis elegans

Shannon C. Brady; Stefan Zdraljevic; Karol W. Bisaga; Robyn E. Tanny; Daniel E. Cook; Daehan Lee; Ye Wang; Erik C. Andersen

Because this gene does not have a predicted non-synonymous variant between the N2 and 633 CB4856 strains, scb-1 gene expression might underlie bleomycin response differences. Potential 634 candidate variants that could cause this expression difference include one variant two kilobases 635 upstream of the gene and one variant in the third intron of scb-1. However, gene expression can 636 be regulated by distant loci, so the identification of the specific variant is difficult. To understand 637 whether natural variation of scb-1 underlies bleomycin-response differences in other strains, we 638 compared the bleomycin-response linkage mapping to a genome-wide association mapping 639 (GWA). We used the HTA to measure median optical density in bleomycin for 83 divergent wild 640 isolates and performed GWA mapping (Figure 7 , File S18, File S19). Six QTL were identified 641 from the GWA, but none of these QTL regions overlapped the QTL from linkage mapping 642 (Figure 7, File S19) . Therefore, the CB4856 strain might have a rare variant that underlies its 643 increase in bleomycin resistance compared to the N2 strain. 644