Ecology and Evolution of Host-Microbe Interactions, Norman Pavelka, Singapore Immunology Network, A*STAR, Singapore
|Starts:||16:00 13 Feb 2014|
|Ends:||17:00 13 Feb 2014|
|What is it:||Seminar|
|Organiser:||Faculty of Life Sciences|
|Who is it for:||University staff, Current University students|
External Speaker, Systems Immunology
Mammalian hosts represent complex environments in which microbes continuously adapt, compete and evolve. Microbial virulence is one of the complex traits under evolutionary pressure that emerges as a result of this dynamic host-microbe interaction. In my lab, we aim to dissect the nature of the host-derived selective pressures that control fungal virulence in the mammalian gastrointestinal (GI) tract, as well as the evolutionary strategies that fungi can come up with to counteract these host-derived control mechanisms. Our previous work in the model organism Saccharomyces cerevisiae has shown the remarkable ability of fungi to adapt to challenging, life-threatening situations. We have uncovered a role for aneuploidy, a karyotypic mutation causing copy number changes of whole chromosomes, as a readily available evolutionary tool to rapidly modify the cellular transcriptome, proteome and phenome of fungi. Whole-chromosome aneuploidy was found to be both required and sufficient to confer selective advantages to yeast cells struggling to survive under genetic, environmental or chemical perturbations. More recently, we also found that some aneuploid karyotypes are sufficient to induce a state of genome instability. Taken together, our work provides evidence that aneuploidy can act both as a driver and as catalyzer of adaptive evolution of fungi, and suggests that aneuploidy might underlie also the adaptation of fungi to the harsh environment encountered within mammalian hosts. Currently, we have set up mouse models of GI colonization and oral-fecal transmission of the human commensal and opportunistic pathogen Candida albicans, to study its virulence evolution when transmitted from host to host. Preliminary results support the hypothesis that prolonged association with mammalian hosts drives phenotypic and karyotypic diversity in initially clonal fungal populations, which might act as a substrate for further selection and evolutionary adaptation. By genetically or chemically perturbing the host, we are now beginning to dissect the role played by the host immune system and the GI microbiota as selective forces driving this evolutionary process.
Dr Pavelka received his Degree in Biotechnology from the University of Milano-Bicocca in 2001 and his Ph.D. in Immunology from the University of Rome “Tor Vergata” in 2006. He formerly worked as a graduate student in Prof Paola Castagnoli’s lab at the University of Milano-Bicocca, where he developed his microarray data analysis skills and contributed to numerous Functional Genomics projects aimed at understanding the role of dendritic cells in host-pathogen interactions. Dr Pavelka then joined Prof Rong Li’s group at the Stowers Institute for Medical Research as a Postdoctoral Research Associate in May 2006, where he published seminal papers on the role of aneuploidy in evolution of yeast cells. While at the Stowers Institute, he collaborated with Dr Michael Washburn, publishing important contributions to the proteomics data analysis field. In October 2010, Dr Pavelka was awarded the A*STAR Investigatorship (Biomedical Sciences) and set up his laboratory at the Singapore Immunology Network in May 2011, to study the ecology and evolution of host-microbe interactions and the genome changes that underlie such complex and dynamic processes. Since 2011, Dr Pavelka is serving as an Associate Editor at Frontiers in Genetics (Section of Bioinformatics and Computational Biology) and in 2013 became Adjunct Assistant Professor at the School of Biological Sciences of the Nanyang Technological University of Singapore.
Additionally there are opportunities to meet with Norman between the dates of Thursday 13th February and Tuesday 18th February (inclusive).
Any interested parties should contact Elaine Bignell (firstname.lastname@example.org), or Carolyn Glynn (email@example.com) directly about this to sort out a meeting time.
Travel and Contact Information
Michael Smith Seminar Room
Michael Smith Building