Candida albicans

Description and significance

Candida albicans is able to sexually reproduce and is a diploid fungus. It is often associated with yeast related diseases in the genitals and in the mouth of animals. It is one of the most common pathogens found in humans and is the source of a variety of different infections. . Like most microorganisms found in the digestive tract of animals, C. albicans falls into a class of relationships that occur between organisms where one benefits and the other is not significantly harmed or benefited. C. albicans can be found in most of the general population causing no detrimental side effects. Although it is not found to be harmful, an overgrowth of C. albicans, known as candidasis, is harmful to the individual. Individuals with a healthy immune system are able to fight off the disease, however in HIV patients with weakened immune systems; it is much more difficult for the disease to be fought off and can lead to more serious problems. In order for the disease to be transmitted to the host, the yeast form of C. albicans responds to changes in the environment, becomes harmful, and changes from a unicellular form into a multicellular.

Genome

C. Albicans was one of the first eukaryotic pathogens chosen for gene sequencing.The genome of Candida albicans was sequenced due to the fact that it is one of the most common human fungal pathogen. Most isolates of C. albicans used for genetic analysis are mostly diploid and some even contain translocations in their genes. Unlike most species that undergo sequencing, a haploid form of C. albicans is unavailable. Due to its extensive use in molecular analyses and virulence in animal models, SC5314(7) was selected for large- scale sequencing. C. albicans was first sequenced at the Stanford DNA Sequencing and Technology Center. The diploid sequence assembly displayed the amount of heterozygosity in the strain SC5314. The results obtained from this along with results from the sequencing afforded many important discoveries in C. albicans development.To put together the C. albicans diploid genome sequence, a commonly used assembly program called the “phrap” was used. Using the phrap, resulted in an assembly in which the products of the overlapping DNA fragments (contigs), were as much as 20% much greater than the size of the haploid genome.The ultimate diploid sequence was disperesed over 412 supercontigs, 146 homologous pairs, 119 phrap contigs, and one supercontig produced from two phrap contigs joined on the basis of GenBank sequence.

References

[1]↑Chibana, H., Magee, B. B., Grindle, S., Ran, Y., Scherer, S. & Magee, P. T. (1998) Genetics 149 , 1739-1752.