Klar A J, Fogel S, Lusnak K
Genetics. 1979 Jul;92(3):777-82. doi: 10.1093/genetics/92.3.777.
Tetrad analysis of MATa/MAT alpha diploids of Saccharomyces cerevisiae generally yields 2 MATa:2MAT alpha meiotic products. About 1 to 1.8% of the tetrads yield aberrant segregations for this marker. Described here are experiments that determine whether the aberrant meiotic segregations at the mating-type locus are ascribable to gene conversions or to MAT switches, that is, to mating-type interconversions. Diploid strains incapable of switching MATa to MAT alpha, or the converse, nevertheless display changes of MATa to MAT alpha, or the reverse. These events must be attributed to gene conversion. Further, we suggest that MATa and MAT alpha alleles may represent nonhomologous sequences of DNA since they fail to display postmeiotic segregations.
对酿酒酵母MATa/MATα二倍体进行四分体分析，通常会产生2个MATa:2个MATα的减数分裂产物。对于这个标记，约1%至1.8%的四分体产生异常分离。本文描述的实验旨在确定交配型位点的异常减数分裂分离是归因于基因转换还是MAT转换，即交配型的相互转换。不能将MATa转换为MATα或反之的二倍体菌株，仍然会出现MATa到MATα或相反的变化。这些事件必定归因于基因转换。此外，我们认为MATa和MATα等位基因可能代表非同源DNA序列，因为它们未表现出减数分裂后分离。
