| Title: | Evolution of mating within the Candida parapsilosis species group |
| Author(s): | Sai S; Holland LM; McGee CF; Lynch DB; Butler G; |
| Address: | "UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland" |
| ISSN/ISBN: | 1535-9786 (Electronic) 1535-9778 (Print) 1535-9786 (Linking) |
| Abstract: | "Candida orthopsilosis and Candida metapsilosis are closely related to Candida parapsilosis, a major cause of infection in premature neonates. Mating has not been observed in these species. We show that approximately 190 isolates of C. parapsilosis contain only an MTLa idiomorph at the mating-type-like locus. Here, we describe the isolation and characterization of the MTL loci from C. orthopsilosis and C. metapsilosis. Among 16 C. orthopsilosis isolates, 9 were homozygous for MTLa, 5 were homozygous for MTLalpha, and 2 were MTLa/alpha heterozygotes. The C. orthopsilosis isolates belonged to two divergent groups, as characterized by restriction patterns at MTL, which probably represent subspecies. We sequenced both idiomorphs from each group and showed that they are 95% identical and that the regulatory genes are intact. In contrast, 18 isolates of C. metapsilosis contain only MTLalpha idiomorphs. Our results suggest that the role of MTL in determining cell type is being eroded in the C. parapsilosis species complex. The population structure of C. orthopsilosis indicates that mating may occur. However, expression of genes in the mating signal transduction pathway does not respond to exposure to alpha factor. C. parapsilosis is also nonresponsive, even when the GTPase-activating protein gene SST2 is deleted. In addition, splicing of introns in MTLa1 and MTLa2 is defective in C. orthopsilosis. Mating is not detected. The alpha factor peptide, which is the same sequence in C. parapsilosis, C. orthopsilosis, and C. metapsilosis, can induce a mating response in Candida albicans. It is therefore likely either that mating of C. orthopsilosis takes place under certain unidentified conditions or that the mating pathway has been adapted for other functions, such as cross-species communication" |
| Keywords: | "Amino Acid Sequence Candida/classification/*genetics/pathogenicity/*physiology Candidiasis Fungal Proteins/genetics/metabolism Humans Infant, Newborn Infant, Newborn, Diseases/microbiology Infant, Premature Molecular Sequence Data Pheromones/genetics/meta;" |
| Notes: | "MedlineSai, Sixiang Holland, Linda M McGee, Conor F Lynch, Denise B Butler, Geraldine eng Research Support, Non-U.S. Gov't 2011/02/22 Eukaryot Cell. 2011 Apr; 10(4):578-87. doi: 10.1128/EC.00276-10. Epub 2011 Feb 18" |
