Septin proteins are conserved structural proteins that often demarcate regions 
of cell division. The essential nature of the septin ring, composed of several 
septin proteins, complicates investigation of the functions of the ring, 
although careful analysis in the model yeast Saccharomyces cerevisiae has 
elucidated the role that septins play in the cell cycle. Mutation analysis of 
nonessential septins in the pathogenic fungus Candida albicans has shown that 
septins also have vital roles in cell wall regulation (CWR), hyphal formation, 
and pathogenesis. While mutations in nonessential septins have been useful in 
establishing phenotypes, the septin defect is so slight that identifying 
causative associations between septins and downstream effectors has been 
difficult. In this work, we describe decreased abundance by mRNA perturbation 
(DAmP) alleles of essential septins, which display a septin defect more severe 
than the defect observed in deletions of nonessential septins. The septin DAmP 
alleles have allowed us to genetically separate the roles of septins in hyphal 
growth and CWR and to identify the cyclic AMP pathway as a pathway that likely 
acts in a parallel manner with septins in hyphal morphogenesis.