ABSTRACTWith the advent of high-throughput DNA sequencing, it is now straightforward and inexpensive to generate high-density small nucleotide polymorphism (SNP) maps. Here we combined high-throughput sequencing with bulk segregant analysis to expedite mutation mapping. The general map location of a mutation can be identified by a single backcross to a strain enriched in SNPs compared to a standard wild-type strain. Bulk segregant analysis simultaneously increases the likelihood of determining the precise nature of the mutation. We present here a high-density SNP map betweenNeurospora crassaMauriceville-1-c (FGSC2225) and OR74A (FGSC2489), the strains most typically used byNeurosporaresearchers to carry out mapping crosses. We further have demonstrated the utility of the Mauriceville sequence and our approach by mapping the mutation responsible for the only existing temperature-sensitive (ts) cell cycle mutation inNeurospora,nuclear division cycle-1(ndc-1). The single T-to-C point mutation maps to the gene encoding ornithine decarboxylase (ODC),spe-1(NCU01271), and changes a Phe to a Ser residue within a highly conserved motif next to the catalytic site of the enzyme. By growth on spermidine and complementation with a wild-typespe-1gene, we showed that the defect inspe-1is responsible for the tsndc-1mutation. Based on our results, we propose changingndc-1tospe-1ndc, which reflects that this mutation results in an ODC with a specific nuclear division defect.
Bulk Segregant Analysis by High-Throughput Sequencing Reveals a Novel Xylose Utilization Gene from Saccharomyces cerevisiae
