摘要：

The ALS1 ( ag glutinin- l ike s equence) gene of Candida albicans encodes a protein similar to alpha-agglutinin, a cell-surface adhesion glycoprotein of Saccharomyces cerevisiae (Hoyer et al. 1995). A central domain of a tandemly repeated 108-bp sequence is found in the ALS1 coding region. This tandem-repeat motif hybridizes to multiple C. albicans genomic DNA fragments, indicating the possibility of other ALS1 -like genes in C. albicans (Hoyer et al . 1995). To determine if these fragments constitute a gene family, tandem-repeat-hybridizing genomic fragments were isolated from a fosmid library by PCR screening using primers based on the consensus tandem-repeat sequence of ALS1 (Hoyer et al . 1995). One group of fosmids, designated ALS3 , encodes a gene with 81% identity to ALS1 . The sequences of ALS1 and ALS3 are most conserved in the tandem-repeat domain and in the region 5′ of the tandem repeats. Northern-blot analysis using unique probes from the 3′ end of each gene demonstrated that ALS1 expression varies, depending on which C. albicans strain is examined, and that ALS3 is hyphal-specific. Both genes are found in a variety of C. albicans and C. stellatoidea strains examined. The predicted Als1p and Als3p exhibit features suggesting that both are cell-surface glycoproteins. Southern blots probed with conserved sequences from the region 5′ of the tandem repeats suggest that other ALS-like sequences are present in the C. albicans genome and that the ALS family may be larger than originally estimated.

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