Monosomic chr5 derivative of laboratory strain of Candida albicans 3153A

Differential expression between monosoic derivative and parental strain of Candida albicans. The important human pathogen Candida albicans possesses an unusual form of gene regulation, in which the copy number of an entire specific chromosome or a large portion of a specific chromosome changes in response to a specific adverse environment, thus, assuring survival. In the absence of the adverse environment, the altered portion of the genome can be restored to its normal condition. One major question is how C. albicans copes with gene imbalance arising by transitory aneuploid states. Here, we compared transcriptomes from two copies of chromosome 5 (Ch5) in a normal diploid strain 3153A and from a single copy of Ch5 in representative derivative Sor55. Statistical analysis revealed that at least 40% of transcripts from the monosomic Ch5 are fully compensated to a disomic level, thus, indicating the existence of a genome-wide mechanism maintaining cell homeostasis. However, a minor portion of transcripts diminished twofold in accordance with what would be expected for Ch5 monosomy. Another minor portion of transcripts, unexpectedly, increased up to twofold and higher then the disomic level, demonstrating indirect control by monosomy. We suggest that C. albicans unusual regulation of gene expression by the loss and gain of entire chromosomes is coupled with widespread compensation of gene dosage at the transcriptional level. The laboratory strain 3153A is a prototrophic laboratory stain of Candida albicans. The strain Sor55 is a representative derivative of 3153A, monosomic for Ch5. Three replicate hybridizations were performed for of each strain. Normalization were done using non-chr5 genes to avoid the potential dosage effects on chr5 genes.