1. Marek Mentel Prednáška, Gymnázium GJH, marec 2012

2. Are eukaryotes all about oxygen?...and what Earth history has to do with it? Marek Mentel Prednáška, Gymnázium GJH, marec 2012

3. Lecture content What are eukaryotes - eukaryotes specific features What are eukaryotes - eukaryotes specific features Eukaryotes origin theories Eukaryotes origin theories Mitochondria types i.e. aerobic and anaerobic mitochondria Mitochondria types i.e. aerobic and anaerobic mitochondriahydrogenosomes mitosomes (cryptons) Energetic metabolism of individual mitochondria forms i.e. respiration Energetic metabolism of individual mitochondria forms i.e. respirationaerobicanaerobic fermentation chemolithotrophy Mitochondria origin in the context of Earth geochemistry changes Mitochondria origin in the context of Earth geochemistry changes

4. Cytology - Prokaryotic & Eukaryotic cells comparison

5. Cytology - Eukaryotic cells specific features Nucleus / EndoMembrane system / Golgi apparatus Cytoskeleton / Flagella & Cilia Endocytosis e.g. Phagocytosis Mitosis Sex – Meiosis & Fertilization Mitochondria Plastids Peroxisome Linear chromosomes (centromere, telomere, telomerase) Spliceosome (spliceosomal Introns splicing - mRNA export coupling)

6. Habitats and Energetics - Prokaryotic & Eukaryotic cells versatility comparison !! not true for eukaryotes !! anaerobic respiration aerobic respiration

7. Eukaryotic cells origin theories review Phagocytosis first / Mitochondria late view Mitochondria first / Phagocytosis late view

8. Eukaryotic cells origin theories - prokaryotes within prokaryotes plausibility Mealybug Planococcus citri endosymbiotic γ-proteobacteria within ß-proteobacteria

9. Eukaryotic cells origin theories - ox-tox hypothesis

10. Eukaryotic cells origin theories - hydrogen hypothesis

11. Aerobic mitochondria Biosynthetic pathways:Heme synthesisBiosynthetic pathways:Heme synthesis Fe-S synthesis Ubiquinone synthesis Metabolism:Amino acidsMetabolism:Amino acidsCarbohydrates Nucleotide & Krebs cycle Lipid Energetics:aerobic respiration – oxidative phosphorylation Energetics:aerobic respiration – oxidative phosphorylation aerobic respiration

12. (facultative) Anaerobic mitochondria Unicellular protists & Metazoa:Ciliates nitrate, nitrite Unicellular protists & Metazoa:Ciliates nitrate, nitrite Fungi nitrate, nitrite, sulfur Nematodes fumarate Plathelminthsfumarate Snailsfumarate Bivalvesfumarate anaerobic respiration Chemolithotrophic mitochondria Metazoa:Bivalves Metazoa:Bivalves Polychaete worm Crustaceans chemolithotrophy – inorganic electron donor (S 2-, HS -, H 2 S)

13. Hydrogenosomes and Mitosomes (Crypton) - MLOs Unicellular anaerobes: Unicellular anaerobes: Parabasalids(Trichomonas) Ciliates(Nyctotherus) Chytridiomycete fungi(Neocallimastix) Amoeboflagellate(Psalteriomonas) Stramenopile(Blastocystis) Hydrogenosome Mitosome fermentation – substrate-level phosphorylation no energy metabolism Mitochondria, Hydrogenosomes, Mitosomes common features: Mitochondria, Hydrogenosomes, Mitosomes common features: double membrane protein targeting / import iron-sulfur clusters synthesis mitochondrial carrier family proteins Diplomonads (Giardia) Entamoebids (Entamoeba) Microsporidia (Encephalitozoon) Apicomplexan (Cryptosporidium)

14. Hydrogenosomes and Mitosomes structure mitochondria hydrogenosome with cristae - N.ovalis hydrogenosome without cristae Neocallimastix patriciarum & Methanogen mitosome - Giardia mitosome - Cryptosporidium& EReticulum

15. (facultative) Anaerobic mitochondria – Fasciola hepatica

16. Anaerobic mitochondria / Hydrogenosome – Nyctotherus ovalis

17. Hydrogenosome – Piromyces sp. E2

18. Mitosome – Giardia intestinalis

19. Earth history - Geological TimeScales P - Pleistocene Holocene eukaryotes origin

20. Geochemical history of Earth – atmosphere oxygenation eukaryotes origin

21. Earth history – significant lag in oceans oxygenation & Canfield oceans chemistry slight atmosphere oxygenation continents weathering sulfate-reducing bacteria radiation

22. Geochemical history of Earth – significant lag in oceans oxygenation & Canfield oceans Anbar & Knoll, 2002 eukaryotes origin

23. Earth history – significant lag in oceans oxygenation & Canfield oceans eukaryotes origin

24. Eukaryotic anaerobes & Proterozoic ocean chemistry Mentel & Martin, 2008 Dietrich, 2006

25. Origins of mitochondria, hydrogenosomes and mitosomes Martin, 2001 Glycolysis - backbone of energy metabolism in Eukaryotes

26. Metabolically flexible mitochondria – Arenicola marina

27. Take home messages: Eukaryotes and Mitochondria Eukaryotes and Mitochondria O 2 Anaerobic mitochondria & eukaryotic anaerobes make sense in Anaerobic mitochondria & eukaryotic anaerobes make sense in light of Proterozoic ocean chemistry Obligate aerobes like ourselves seems to represent specialized Obligate aerobes like ourselves seems to represent specialized adaptation to recently oxygenated habitats Mitochondria: Mitochondria:aerobicanaerobicchemolithotrophic hydrogenosomes – not uniform mitosomes genome genome cristae cristae oxidative phosphorylation substrate-level phosphorylation no energy metabolism

28. Take home messages: ? what makes mitochondria an essential compartment for eukaryotic cell – where is the limit for its reduction not energy metabolism not energy metabolism - mitosomes - cryptic mitochondria (Cryptosporidium parvum) iron-sulfur cluster biosynthesis iron-sulfur cluster biosynthesis - mitosomes () - mitosomes (Giardia intestinalis (syn. lamblia)) - cryptic mitochondria (Cryptosporidium parvum) - mitochondria (yeast) geochemical Earth history (changing Earth) geochemical Earth history (changing Earth) & Eukaryotes evolution Eukaryotes evolution interconnection