Centre Algatech

         GROUP MEMBERS
                                                                                                                                Jan Janouškovec, Eva Horáková, Lucie Fraitová, Jan Michálek, Daniela Hávová, Ayca Fulya Üstüntanir Dede, Chetan Paliwal, Martin Lukeš, year 2022

ALGAL EVOLUTION AND ECOLOGY 

We use computational and experimental methods to advance three related research topics:  

Evolution of photosynthesis

Many fundamental questions about how photosynthesis emerged and spread in eukaryotes can be advanced by new approaches. Following on earlier work on plastid endosymbiosis and reductive evolution [1, 2, 3, 4] we seek to understand the principles of photosynthesis and endosymbiosis on organismal and genetic levels. Currently, we are studying the evolution of chlorophylls and high light inducible proteins (HLIPs). We also keep an interest in understanding plastid phylogeny, genome structure, genetic code and DNA replication.

                                                              
Fig. 1: Genes encoded in apicomplexan and dinoflagellate plastid genomes [6]                 Fig. 2:  Split PsaA and AtpB proteins in the plastid of Chromera velia [2]                                                                            

                                                  
Metabolism in plastids and mitochondria

Besides photosynthesis and respiration, endosymbiotic organelles have other important roles in cells. For example, non-photosynthetic plastids in most apicomplexans and dinoflagellates are required for producing essential metabolites, such as fatty acids and heme [3, 5, 6]. Some single-celled eukaryotes possess organellar metabolism that is absent in animal or plant models; others use known pathways in new contexts [7]. Our current focus is to understand the phosphonate pathway and chlorophyll metabolism in different eukaryotes.     

                                                                                                                                                                                                                                                                                                                 Fig. 3: Phosphonate biosynthesis and degradation in eukaryotes

                                                                          
Protist diversity and ecology

Many algae, heterotrophic flagellates and parasites are understudied because they are difficult to maintain in laboratory conditions. Yet, these protists can be widespread and important in the environment. From the discovery of chromerids [8] to sequencing enigmatic heterotrophs [7, 9] identifying new parasites with plastids [6, 10], we have worked to explore the eukaryotic tree of life. Currently, we apply single-cell sequencing methods to studying the diversity and biology of parasite-host interactions.

Fig. 4: Parasitism, photosynthesis and non-photosynthetic        Fig. 5: Chromerid algae and apicomplexan parasites    
plastid metabolism on the Alveolate tree of life [6]           

Find more about our research in the Projects tab on the left. If you are interested to discuss these topics or work with us email Jan at janouskovec(at)alga.cz

Selected publications (full-text links in the Publications tab on the left):

[1] Janouškovec, J, Horák, A, Oborník, M, Lukeš, J, Keeling PJ (2010). A common red algal origin of the apicomplexan, dinoflagellate, and heterokont plastids. PNAS 107, 10949–54.

[2] Janouškovec, J, Sobotka, R, Lai, D-H, Flegontov, P, Koník, P, Komenda, J, Ali, S, Prášil, O, Pain, A, Oborník, M, Lukeš, J, Keeling, PJ (2013a). Split photosystem protein, linear-mapping topology, and growth of structural complexity in the plastid genome of Chromera velia. Mol Biol Evol 30, 2447–62.

[3] Janouškovec, J, Tikhonenkov, DV, Burki, F, Howe, AT, Kolísko, M, Mylnikov, AP, Keeling, PJ (2015). Factors mediating plastid dependency and the origins of parasitism in apicomplexans and their close relatives. PNAS 112, 10200–07.

[4] Janouskovec, J, Keeling, PJ: Evolution (2016). Causality and the origin of parasitism. Curr Biol 26, R174–R177.

[5] Janouškovec, J, Gavelis, GS, Burki, F, Dinh, D, Bachvaroff, TR, Gornik, SG, Bright, KJ, Imanian, B, Strom, SL, Delwiche, CF, Waller, RF, Fensome, RA, Leander, BS, Rohwer, FL, Saldarriaga, JF (2017a). Major transitions in dinoflagellate evolution unveiled by phylotranscriptomics. PNAS 114, E171–E180.

[6] Janouškovec, J, Paskerova, GG, Miroliubova, TS, Mikhailov, KV, Birley, T, Aleoshin, VV, Simdyanov, TG (2019). Apicomplexan-like parasites are polyphyletic and widely but selectively dependent on cryptic plastid organelles. eLife 8, e49662.

[7] Janouškovec, J, Tikhonenkov, DV, Burki, F, Howe, AT, Rohwer, FL, Mylnikov, AP, Keeling, PJ (2017b). A new lineage of eukaryotes illuminates early mitochondrial genome reduction. Curr Biol 27, 3717-3724.e5.

[8] Moore, RB, Oborník, M, Janouškovec, J, Chrudimský, T, Vancová, M, Green, DH, Wright, SW, Davies, NW, Bolch, CJS, Heimann, K, Slapeta, J, Hoegh-Guldberg, O, Logsdon, JM, Carter, DA (2008). A photosynthetic alveolate closely related to apicomplexan parasites. Nature 451, 959–63.

[9] Janouškovec, J, Tikhonenkov, DV, Mikhailov, KV, Simdyanov, TG, Aleoshin, VV, Mylnikov, AP, Keeling, PJ (2013b). Colponemids represent multiple ancient alveolate lineages. Curr Biol 23, 2546–52.

[10] Janouškovec, J, Horák, A, Barott, KL, Rohwer, FL, Keeling, PJ (2012). Global analysis of plastid diversity reveals apicomplexan-related lineages in coral reefs. Curr Biol 22, R518-9,.