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Updated: May 14, 2026
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Determination of the Mating Efficiency of Haploids in Saccharomyces cerevisiae
Published on: December 2, 2022
The 'obligate diploid' Candida albicans forms mating-competent haploids
Meleah A Hickman1, Guisheng Zeng, Anja Forche
1Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Nature
|February 1, 2013
Summary
The fungal pathogen Candida albicans can exist in a viable haploid state, challenging its long-held diploid classification. This haploid form can revert to diploidy, offering new avenues for genetic research.
Area of Science:
- Microbiology
- Mycology
- Genetics
Background:
- Candida albicans is a prevalent human fungal pathogen.
- It was previously considered an obligate diploid organism.
- Recessive lethal mutations are thought to be widespread in its genome.
Purpose of the Study:
- To investigate the existence and characteristics of a haploid state in Candida albicans.
- To explore the mechanisms of haploid formation and its implications for fungal biology.
- To develop stable haploid strains for enhanced genetic analysis.
Main Methods:
- Derivation of haploid Candida albicans from diploid cells under in vitro and in vivo conditions.
- Analysis of morphogenetic changes in haploid cells, including yeast-hyphal transition and white-opaque switching.
- Assessment of mating efficiency between haploid cells and regeneration of the diploid form.
- Construction of stable haploid strains with multiple auxotrophies.
Main Results:
- Candida albicans demonstrated a viable haploid state arising from chromosome loss.
- Haploid cells exhibited conserved morphogenetic capabilities, including mating.
- Haploid cells efficiently mated to regenerate diploidy, restoring heterozygosity and fitness.
- Homozygous diploids arose spontaneously but showed reduced fitness, indicating transient stability.
- Stable auxotrophic haploid strains were successfully created.
Conclusions:
- Candida albicans possesses a viable haploid phase, contrary to previous assumptions.
- The haploid state is morphogenetically versatile and capable of efficient diploid restoration.
- The development of stable haploid strains significantly advances genetic manipulation and study of this pathogen.
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