Format

Send to

Choose Destination
Genetics. 2005 Apr;169(4):1883-90. Epub 2005 Feb 3.

Increased virulence and competitive advantage of a/alpha over a/a or alpha/alpha offspring conserves the mating system of Candida albicans.

Author information

1
Department of Biological Sciences, The University of Iowa, Iowa City, 52242-1324, USA.

Abstract

The majority of Candida albicans strains in nature are a/alpha and must undergo homozygosis to a/a or alpha/alpha to mate. Here we have used a mouse model for systemic infection to test the hypothesis that a/alpha strains predominate in nature because they have a competitive advantage over a/a and alpha/alpha offspring in colonizing hosts. Single-strain injection experiments revealed that a/alpha strains were far more virulent than either their a/a or alpha/alpha offspring. When equal numbers of parent a/alpha and offspring a/a or alpha/alpha cells were co-injected, a/alpha always exhibited a competitive advantage at the time of extreme host morbidity or death. When equal numbers of an engineered a/a/alpha2 strain and its isogenic a/a parent strain were co-injected, the a/a/alpha2 strain exhibited a competitive advantage at the time of host morbidity or death, suggesting that the genotype of the mating-type (MTL) locus, not associated genes on chromosome 5, provides a competitive advantage. We therefore propose that heterozygosity at the MTL locus not only represses white-opaque switching and genes involved in the mating process, but also affects virulence, providing a competitive advantage to the a/alpha genotype that conserves the mating system of C. albicans in nature.

PMID:
15695357
PMCID:
PMC1449611
DOI:
10.1534/genetics.104.038737
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center