X–XI. Yeast mapping reports. The use of random‐breakage mapping to locate the genes APN1 and YUH1 in the Saccharomyces genome, and to determine gene order near the left end of chromosome XI

We have used the previously described technique of random‐breakage mapping to locate the two yeast genes APN1 and YUH1. The APN1 locus is located ∼235 kb from the left telomere of chromosome XI, and shows weak (∼53 cM) genetic linkage to ura1. The YUH1 locus is located ∼140 kb from the right telomere of chromosome X, and genetically maps 3·6 cM distal to cdc11. In addition, we show by random‐breakage mapping that TRP3 is located ∼45 kb from the left telomere of chromosome XI, whereas FAS1 is ∼110 kb from the same telomere. This supports a gene order on the left distal portion of chromosome XI that agrees with other physical reports but is inverted with respect to Edition 11 of the published genetic map. This report confirms that random‐breakage mapping is a rapid and convenient method of locating cloned genes.