Cover photograph (Copyright © 2001, American Society for Microbiology. All rights reserved.): In Saccharomyces cerevisiae (top two rows), expression of Candida albicans INT1 induces filamentous growth (left) and highly polarized actin cortical patches (top right). SLA2 is required for INT1-induced polarized growth (second row, middle [sla2 strain]) yet is not required for polarized growth in a cdc3 mutant strain (second row, right [sla2 cdc3 strain]). In C. albicans (bottom two rows), the wild type (SLA2/SLA2 [left]) and heterozygotes (Sla2/sla2 [middle]) form filamentous colonies on milk-Tween agar (third row) and grow as hyphae in serum (fourth row). In contrast, sla2/sla2 strains (right panels) fail to form filamentous colonies or hyphal cells in these media. (See related article on page 1272.)