A*STAR scientists from the Institute of Molecular and Cell Biology (IMCB) have identified what eluded yeast scientists for the past 100 years, by constructing stable haploid strains of Candida albicans, the most prevalent human fungal pathogen. This discovery, jointly made by two teams of scientists led by Prof Wang Yue of IMCB and Prof Judith Berman of the University of Minnesota, will enable scientists to effectively target and treat infections by Candida albicans. The findings, "The 'obligate diploid' Candida albicans forms mating-competent haploids", were published in the online issue of Nature on 30 January 2013.
Candida albicans ranks among the top four microbial pathogens in hospital-acquired infections of the blood, which has a mortality rate of as high as 45%. Currently, the choice of drugs for treating infections by this pathogen is limited, and drug-resistance has emerged worldwide, posing a great challenge to medicine.
Importance of the discovery
Nearly all other fungi have a haploid and a diploid phase in their life cycle, enabling the haploid cells to mate and generate genetic variations. However, up till this recent discovery, yeast scientists the world over had been unable to identify a haploid phase of this fungus.
Commenting on the significance of the discovery, Dr Mohan Balasubramanian, Senior Investigator at Temasek Lifesciences Laboratory and a leading yeast geneticist in the world, said, "The scientists show that the human pathogenic yeast Candida albicans, long thought of as always having two copies of each chromosome and no sexual reproduction in its life, in fact can and does exist as a sexually reproducing cell carrying only one copy of its genome."
Without a haploid phase, it is indeed extremely difficult for scientists to carry out genetic screens in fungi as this would require the precise targeting of both copies of a gene in a diploi
|Contact: Vithya Selvam|
Agency for Science, Technology and Research (A*STAR), Singapore