Lucía F. Zacchi

E-mail: zacch002@umn.edu

Thesis Advisor: Dana Davis

Year entered: 2004

Degrees received:
B.S., Microbiology, Universidad Nacional de Rio Cuarto, Cordoba, Argentina, 2003

Honors and awards:

• MICaB Career Development Committee 2007-2009
• Golden Pipetman Award. MICaB Program 2008
• 2009 Milne-Brandenburg MICaB Student Travel Award Spring 2009
• COGS Travel Award. University of Minnesota 2009
• GAPSA Travel Award. University of Minnesota

Thesis research:
Many pathogenic microorganisms have the ability to generate phenotypic variants that allow them to escape immune surveillance and adapt to rapidly changing microenvironments. Candida albicans is a commensal/opportunistic pathogen responsible for the majority of invasive fungal infections in the US. This fungus undergoes a process called phenotypic switching, characterized by the spontaneous appearance of colonies with altered morphology. This low frequency, reversible switch is also accompanied by changes in expression of other traits, including several virulence factors. Phenotypic switching is associated with pathogenesis and constitutes a way to obtain phenotypic variability and increase the overall fitness of the fungal population. The molecular mechanism that governs phenotypic switching in C. albicans is still unknown. Studies performed in other organisms and in cancer biology have suggested that epigenetic mechanisms (such as histone modifications) and chromosomal instability could be associated with the regulation of this and similar processes. MDS3 is a gene required for inhibition of phenotypic switching in C. albicans. In the absence of MDS3 the frequency of phenotypic switching greatly increases. We hypothesize that Mds3 inhibits phenotypic switching through a molecular mechanism related to gene silencing or to chromosomal instability