Insights on life cycle and cell identity regulatory circuits for unlocking genetic improvement in Zygosaccharomyces and Kluyveromyces yeasts

Abstract

Evolution has provided a vast diversity of yeasts that play fundamental roles in nature and society. This diversity is not limited to genotypically homogenous species with natural interspecies hybrids and allodiploids that blur species boundaries frequently isolated. Thus, life-cycle and the nature of breeding systems have profound effects on genome variation, shaping heterozygosity, genotype diversity and ploidy level. The apparent enrichment of hybrids in industry-related environments suggests that hybridisation provides an adaptive route against stressors and creates interest in developing new hybrids for biotechnological uses. For example, in the Saccharomyces genus where regulatory circuits controlling cell-identity, mating competence and meiosis commitment have been extensively studied, this body of knowledge is being used to combine interesting traits into synthetic F1 hybrids, to by-pass F1 hybrid sterility, and to dissect complex phenotypes by bulk segregant analysis. Although there is less known about these aspects in other industrially-promising yeasts, advances in whole genome sequencing and analysis are changing this and new insights are being gained, especially in the food-associated genera Zygosaccharomyces and Kluyveromyces. We discuss this new knowledge and highlight how deciphering cell identity circuits in these lineages will contribute significantly to identify the genetic determinants underpinning complex phenotypes and open new avenues for breeding programmes.

The evolution and role of the periplasmic asparaginase Asp3 in yeast

“…Genetic regulatory circuits are complex systems and already there are multiple examples of rewiring over the course of yeast evolution (Solieri et al . 2021 ). Thus, while components are conserved, it cannot be assumed that nitrogen regulatory systems function identically in S. cerevisiae and S. uvarum .…”

“…Interspecific hybridization has also emerged as a critical means of adapting to anthropogenic environments, with multiple instances from the Saccharomyces genus (Alsammar and Delneri 2020 ) and from other budding yeasts (Solieri et al . 2021 ).…”

A COST Action on microbial responses to low pH: Developing links and sharing resources across the academic-industrial divide

“…Cellular rewiring was also used to improve the robustness of the yeast Saccharomyces cerevisiae against acetic acid released from lignocellulosic biomasses, by the modification of a hub element. Such approaches can help to promote an effective and viable implementation of microbialbased processes at industrial level [12,13].…”