A single SNP, G929T (Gly310Val), determines the presence of a functional and a non-functional allele of HIS4 in Candida albicans SC5314: detection of the non-functional allele in laboratory strains.
Candida albicans is a diploid organism that exhibits high levels of heterozygosity. Although the precise manner by which this heterozygosity provides advantage for the commensal/pathogenic life styles of C. albicans is not known, heterozygous markers are themselves useful for studying genomic rearrangements, which occur frequently in C. albicans. Treatment of CAI-4 with UV light yielded histidine auxotrophs which could be complemented by HIS4, suggesting that strain CAI-4 is heterozygous for HIS4. These auxotrophs appeared to have undergone mitotic recombination and/or chromosome loss. As expected from a heterozygote, disruption of the functional allele of HIS4 resulted in a his4::hisG-URA3-hisG strain that is auxotrophic for histidine. Sequencing of random clones of the HIS4 ORF from CAI-4 and its precursor SC5314 revealed the presence of 11 SNPs, seven synonymous and four non-synonymous. Site-directed mutagenesis indicates that only one of those SNPs, T929G (Gly310Val), is responsible for the non-functionality of the encoded enzyme. HIS4 analysis of five commonly used laboratory strains is reported. This study provides a new, easily measured nutritional marker that can be used in future genetic studies in C. albicans.
Gómez-Raja
Jonathan
J
Departamento de Ciencias Biomédicas, Area Microbiología, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain.
Andaluz
Encarnación
E
Magee
Beatrice
B
Calderone
Richard
R
Larriba
Germán
G
D000483:Alleles; D019943:Amino Acid Substitution / Q000235:genetics*; D000619:Aminohydrolases / Q000235:genetics / Q000378:metabolism*; D002176:Candida albicans / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005816:Genetic Complementation Test; D006639:Histidine / Q000096:biosynthesis; D016254:Mutagenesis, Insertional; D016297:Mutagenesis, Site-Directed; D020641:Polymorphism, Single Nucleotide; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D014466:Ultraviolet Rays
D004271:DNA, Fungal; D005656:Fungal Proteins; D006639:Histidine; D000619:Aminohydrolases