Aneuploidy in yeast: Segregation error or adaptation mechanism?

Area of Science:

• Genetics
• Evolutionary Biology
• Microbiology

Background:

• Aneuploidy, the alteration of chromosome number, is typically detrimental but can offer adaptive advantages under stress.
• Yeast species like Saccharomyces, Candida, and Cryptococcus exhibit varying aneuploidy rates.
• Hybridization between divergent genomes can exacerbate aneuploidy due to meiotic errors.

Purpose of the Study:

• To review the prevalence of aneuploidy in key yeast genera and their hybrids.
• To analyze the relationship between aneuploidy, chromosome size, and environmental stressors.
• To explore the evolutionary implications of aneuploidy, particularly in the context of hybridization and adaptation.

Main Methods:

• Literature review of aneuploidy prevalence and associated factors in selected yeast species.
• Analysis of existing data on chromosome size and stress-induced aneuploidy.
• Discussion of the interplay between hybridization, meiotic errors, and aneuploidy.

Main Results:

• Aneuploidy occurs across Saccharomyces, Candida, and Cryptococcus, influenced by chromosome size and environmental conditions.
• Hybridization significantly increases aneuploidy rates in offspring due to meiotic instability.
• Both hybridization and aneuploidy appear to be favored under environmental stress.

Conclusions:

• Aneuploidy can be a significant driver of microbial evolution, facilitating adaptation and innovation.
• The co-occurrence of hybridization and aneuploidy presents a potent evolutionary mechanism for yeasts.
• Further research is warranted to understand the evolutionary significance of hybrid-induced aneuploidy in microbial diversification.