Cloning and Functional Analysis of ALS Family Genes from Candida albicans.

With a 0.5 kb probe of CX2, distribution of CX2 tandem repeats was studied in different C.albicans strains. Results suggest that all the C.albicans strains tested contained the tandem repeat. In order to verify if the expression of CX2 was hyphal specific, its expression was analyzed under various inductive and non-inductive conditions. With CX2 0.5 kb probe, Northern hybridization analysis confirmed that it was specifically in hyphae. The result of chromosomal localizationtion and genomic Southern blot analysis suggested that there were other genes containing the tandem repeat besides of ALS1. A C.albicans s genomic DNA library was screened with the CX2 0.5 kb probe and several positive recombinant lambda phages were obtained. After endonuclease identification, subcloning, and sequence analysis, several ALS family genes were cloned. No.1 lambda phage DNA contained ALS4, No.4 lambda phage DNA contained ALS1, No.6 lambda phage DNA contained ALS3. To study the role of ALS family genes in yeast-hyphal transition, als1/ALS1 mutant was constructed by homologous recombination. The ability to form hyphae was tested in different inductive culturing conditions. Defective hyphal growth were observed in some solid media.