We are a research team based at Charles University in Prague. We are evolutionary protistologists which means our interest is nothing less than origin and evolution of eukaryotic life.
Our research focuses on two groups of organisms: Euglenida and Preaxostyla, both of which are members of Excavata supergroup.
We are particularly interested in evolution of their unusual semi-autonomous organelles: highly reduced or even completely lost mitochondrion-like organelle of anaerobic Preaxostyla and secondary plastid of photosynthetic euglenids.
Both of these areas of research provide insight into organelle origin and evolution of their structure, molecular biology, transport, targeting, biogenesis, genome composition, molecular genetics mechanisms and biochemical pathways. We also study the phenomenon of lateral gene transfer which plays important role in some of these processes.
Preaxostyla, living exclusively in oxygen-depleted environments, are one of the least studied protist lineages. We believe these organisms can give us priceless insights into the reductive evolution of mitochondria. Paratrimastix pyriformis belongs to a basal assemblage of free-living Preaxostyla, formerly grouped under a single genus "Trimastix". We study the reduced mitochondrion of Paratrimastix in order to expose the physiological role of the organelle. Our second organisms of interest are oxymonads, which are all living inside guts of various animals and are the largest known group of eukaryotes without any evidence of mitochondrion or related structures. Our investigation of genus Monocercomonoides is focused on the intriguing possibility that this organism indeed completely lost the mitochondrion, a cellular structure that has been long thought to be essential for all eukaryotic organisms.
In our lab we focus on:
- transcriptomics and genomics of oxymonads and Paratrimastix
- cellular localization of potentially mitochondrial proteins
- metabolism connected with anaerobiosis and the putative loss of mitochondrion
- iron-sulfur clusters assembly pathways
- symbiosis of oxymonads and their ecto- and endosymbiotic prokaryotes
- diversity of oxymonads
Euglenids are a group of mostly freshwater flagellates. Their mitochondria are unusual in both structure and molecular genetics. Many euglenids have firm but flexible pellicle and are capable of metaboly, a typical euglenoid movement. Euglenids are well known for their nutritional modes diversity. The ancestral and most widespread mode of nutrition among euglenids is heterotrophy (bacteriovory, eukaryovory and primary osmotrophy). However, one monophyletic group, the euglenophytes, acquired a green secondary plastid and use photosynthesis as the main energy source. This plastid is derived from prasinophyte alga and has three envelope membranes. Light perceiving eyespot of unclear evolutionary origin is present in these organisms. The euglenophytes are still able to survive in dark by switching temporarily to heterotrophy; this feature this feature enabled the origin of several secondarily osmotrophic species with non-photosynthetic colorless plastids. Rapaza viridis, recently discovered mixotrophic lineage requires both photosynthesis and eukaryotic prey for survival.
In our lab we focus on:
- transcriptomics and plastid genomics of euglenids and plastid-related algae
- lateral gene transfer that accompanied the origin of plastid
- plastid proteomics and protein import in Euglena gracilis
- lipid analysis of euglenid chloroplast
- environmental sequencing in search for relatives of the plastid ancestor
- heterotrophic euglenids diversity