CLONING AND CHARACTERIZATION OF ECE1, A GENE EXPRESSED IN ASSOCIATIONWITH CELL ELONGATION OF THE DIMORPHIC PATHOGEN CANDIDA-ALBICANS

The gene ECE1 (extent of cell elongation 1) was isolated by differenti al hybridization screening of a Candida albicans cDNA library by using probes derived from populations of yeast cells or hyphae. Expression of this gene was not detected when C. albicans grew as a budding yeast cell but was observed within 30 min after cells had been induced to f orm hyphae. In all strains tested, regardless of the induction signal, ECE1 expression correlated with the extent of cell elongation. The ge nomic version of ECE1 was cloned and sequenced. The deduced 271-amino- acid polypeptide consisted of eight tandem repeats of a degenerate 34- amino-acid sequence which contained no discernible homology with other known sequences. An ECE1 null mutant displayed no morphological alter ations, which demonstrated that ECE1 is not essential for cell elongat ion or hypha formation despite the strict morphological association of its expression.