Wickner R B
Genetics. 1979 Jul;92(3):803-21. doi: 10.1093/genetics/92.3.803.
A triploid (3n) strain of Saccharomyces cerevisiae was constructed carrying a standard marker on each of chromosomes 1 through XVII in the -/+/+ configuration. This is called a "supertriploid." Meiotic spores from this strain (n + approximately n/2) were mated with a haploid (n) carrying an unmapped mutation. Meiotic analysis of each zygote clone (2n + approximately n/2) produced in this way resulted in elimination of an average of 4.2 chromosomes as the possible location of the unmapped marker. The distribution of extra chromosomes in the 2n + approximately n/2) strains was nearly random. Meiotic segregrants of these crosses carrying the unmapped mutation in the -/+ configuration were then crossed with multiply marked haploid strains to further narrow the possible location of the unmapped mutation to a single chromosome. Scoring of markers by complemention tests was simplified by mating spore clones with mixtures of a and alpha strains, each pair carrying the same set of markers. Using this new, more rapid method ("supertriploid mapping"), eight genes required for the maintenance of the killer plasmid were located on the genetic map of S. cerevisiae.
构建了一种酿酒酵母的三倍体（3n）菌株，其1号至17号染色体上均带有标准标记，呈-/+ / +构型。这被称为“超级三倍体”。该菌株的减数分裂孢子（n + 约n/2）与携带一个未定位突变的单倍体（n）进行交配。对由此产生的每个合子克隆（2n + 约n/2）进行减数分裂分析，结果平均消除了4.2条染色体，作为未定位标记的可能位置。在2n + 约n/2）菌株中额外染色体的分布几乎是随机的。然后将这些携带-/+构型未定位突变的杂交后代的减数分裂分离株与多重标记的单倍体菌株杂交，以进一步将未定位突变的可能位置缩小到一条染色体上。通过将孢子克隆与a型和α型菌株的混合物交配来进行互补测试对标记进行评分，每对菌株携带相同的一组标记，从而简化了评分过程。使用这种新的、更快速的方法（“超级三倍体定位”），确定了维持杀伤质粒所需的8个基因在酿酒酵母遗传图谱上的位置。
