The yeast Saccharomyces cerevisiae is one of the best-understood biological systems and can produce numerous useful compounds. Sexual hybridization (mating) can drive dramatic evolution of yeasts by the inheritance of half of the parental genomic information from each cell. Unfortunately, half of the parental genomic information is lost in individual cells in the next generation. Additionally, recombination of homologous chromosomes during meiosis gives rise to diversity in the next generation; hence, it is commonly employed to identify targets from diverse cell populations, based on the mating machinery. Here, we established a system for generating polyploids that inherit all genetic information from the parental strains via artificial mating-type conversion and repetitive mating. We prepared α-type haploid strains whose chromosomes were tagged with genes encoding fluorescent proteins or transcriptional factors. Only the mating-type locus was successfully converted from α-type to a-type sequence by the endonuclease Ho, and the resultant a-type cells mated with each α-type haploid to yield an a/α-type diploid strain with all genetic information from both parental strains. Importantly, we repeatedly converted the mating-type of polyploid cells to obtain a-type cells capable of mating with α-type cells. This approach can potentially facilitate yeast-strain development with unparalleled versatility, utilizing vast available resources.

中文翻译：

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人工交配类型转换和重复交配以产生多倍体

酵母酿酒酵母是最易理解的生物系统之一，可产生许多有用的化合物。有性杂交（交配）可以通过继承每个细胞中一半的亲本基因组信息来推动酵母的急剧进化。不幸的是，下一代的个体细胞中丢失了一半的亲本基因组信息。另外，在减数分裂过程中同源染色体的重组引起了下一代的多样性。因此，基于交配机制，它通常用于从不同的细胞群中鉴定靶标。在这里，我们建立了一个生成多倍体的系统，该多倍体通过以下途径从亲本菌株继承所有遗传信息：人工交配型转换和重复交配。我们制备了α型单倍体菌株，其染色体用编码荧光蛋白或转录因子的基因标记。仅交配型基因座从α型成功地转换为一个由内切核酸酶何型序列，将得到的一型细胞交配与每个α型单倍体以产生一个/α型二倍体菌株所有遗传来自两个亲本菌株的信息。重要的是，我们反复转换了多倍体细胞的交配型以获得能够与α型细胞交配的a型细胞。这种方法可以利用大量可用资源，以无与伦比的多功能性促进酵母菌株的开发。