In fungi, glycosylphosphatidylinositol-modified (GPI) proteins participate in many cellular processes including the construction, maintenance and remodelling of the cell wall, cell to cell adhesion and adhesion to host tissues and medical devices. The sequencing of the entire genome has allowed the prediction of the complete repertoire of GPI-proteins in Candida albicans. De Groot et al. (Yeast 20:781, 2003) have made an in silico analysis of C. albicans genome by using an algorithm to identify an omega site of covalent GPI attachment at the C-termini and recognized 49 uncharacterized ORFs predicted to code proteins with no homology to known or putative GPI-proteins (named Pga for predicted-GPI-anchored in accordance with CandidaDB). We used Northern blot analysis to determine if the expression of 12 PGA genes is morphogenically regulated. We detected transcripts for all PGA genes in cells growing at 30°C (uninduced yeast growth), 37°C (induction of pseudohyphal growth) and 37°C plus 20% serum (induction of hyphal growth). However, some genes (PGA58, PGA55, PGA13 and PGA61) have their transcription increased (75-500%) when cells are induced by temperature and/or temperature plus serum (filamentous growth). Interestingly, PGA gene expression is repressed by a negative regulator of filamentation (TUP1). These results confirm and extend data previously obtained by microarray analysis. Since PGA genes are unique to C. albicans, and since their expression is under control of a regulator of filamentous growth, which is related to increased adhesiveness, they may have an important role in its pathogenesis.