Hemin induces typical filamentation response

Candida albicans can use external hemin as an alternative to elemental iron. TheMartinez lab reported that hemin also specifically acts as an inducer of filamentation. Weinvestigated this phenomenon among 26 diverse C. albicans isolates and found naturalvariation in response to hemin. In addition, we observed that hemin supplementationimproves biofilm formation of its strong responders. The mechanism by which heminpromotes filamentation and morphological change is not known. To develop anunderstanding, RNA seq was performed to compare hemin-induced filamentation withneutral pH-induced filamentation, a well-studied control condition. Our data analysisshowed that hemin addition induces typical hyphal-associated genes which were alsoinduced by neutral pH, and unique hemin acquisition and metabolism genes. Furthermore,our results revealed that hemin acquisition genes are not required for filamentation, but aheme oxygenase is required for biofilm formation under exposure to excess hemin. Takentogether, my work establishes that hemin addition induces a typical filamentationresponse