School of Biological Sciences, University of Auckland, Auckland 1142, New Zealand.
School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand.
FEMS Yeast Res. 2022 Apr 26;22(1). doi: 10.1093/femsyr/foac017.
Saccharomyces cerevisiae is an exceptional genetic system, with genetic crosses facilitated by its ability to be maintained in haploid and diploid forms. Such crosses are straightforward if the mating type/ploidy of the strains is known. Several techniques can determine mating type (or ploidy), but all have limitations. Here, we validate a simple, cheap and robust method to identify S. cerevisiae mating types. When cells of opposite mating type are mixed in liquid media, they 'creep' up the culture vessel sides, a phenotype that can be easily detected visually. In contrast, mixtures of the same mating type or with a diploid simply settle out. The phenotype is observable for several days under a range of routine growth conditions and with different media/strains. Microscopy suggests that cell aggregation during mating is responsible for the phenotype. Yeast knockout collection analysis identified 107 genes required for the creeping phenotype, with these being enriched for mating-specific genes. Surprisingly, the RIM101 signaling pathway was strongly represented. We propose that RIM101 signaling regulates aggregation as part of a wider, previously unrecognized role in mating. The simplicity and robustness of this method make it ideal for routine verification of S. cerevisiae mating type, with future studies required to verify its molecular basis.
酿酒酵母是一种特殊的遗传系统，其能够以单倍体和二倍体形式存在，这使其遗传杂交变得更加容易。如果知道菌株的交配型/倍性，这种杂交就很简单。有几种技术可以确定交配型（或倍性），但都有局限性。在这里，我们验证了一种简单、廉价且强大的方法来鉴定酿酒酵母的交配型。当具有相反交配型的细胞在液体培养基中混合时，它们会沿着培养容器的侧面“爬行”，这种表型可以很容易地通过肉眼观察到。相比之下，相同交配型的混合物或二倍体则会沉淀下来。在一系列常规生长条件下，使用不同的培养基/菌株，这种表型可以观察到几天。显微镜观察表明，交配过程中的细胞聚集是导致这种表型的原因。酵母敲除集分析鉴定出了 107 个与爬行表型相关的必需基因，这些基因富集了与交配特异性相关的基因。令人惊讶的是，RIM101 信号通路被强烈代表。我们提出，RIM101 信号调节聚集，作为其在交配中更广泛的、以前未被认识到的作用的一部分。这种方法的简单性和稳健性使其成为鉴定酿酒酵母交配型的理想选择，未来的研究需要验证其分子基础。
