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The development of the new genetic system of meiosis in the Eukaryotes and the mechanisms of speciation & coexistence. Bas Kooijman Dept theoretical biology Vrije Universiteit Amsterdam Bas@bio.vu.nl http://www.bio.vu.nl/thb /. Amsterdam, 2008/04/24. Central metabolism.
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The development of the new genetic system of meiosis in the Eukaryotes and the mechanisms of speciation & coexistence Bas Kooijman Dept theoretical biology Vrije Universiteit Amsterdam Bas@bio.vu.nl http://www.bio.vu.nl/thb/ Amsterdam, 2008/04/24
Central metabolism • Adenosine Tri-Phosphate (ATP) • 5 106 molecule in 1 bacterial cell • 2 seconds of synthetic work • mean life span: 0.3 seconds
Cells as metabolic units bacteria 2.5 Bacteria no nuclear membrane some species have cells filled with membranes, other only have a plasma membrane From: Mader, 1993 Biology, WCB
Cells as metabolic units animal cells 2.5 Animal cells have a membrane around the nucleus, mitochondria From: Mader, 1993 Biology, WCB
Cells as metabolic units plant cells 2.5 Plant cells have a membrane around the nucleus, mitochondria, chloroplasts and other cell organelles From: Mader, 1993 Biology, WCB
Mitochondrion & Chloroplast reciprocal syntrophy is the key to homeostasis & controls dynamics oxydative photosynthesis CO2 O2 photorespiration 4 hν + 2 H2O CH2O + H2O
Heterotrophic Hepatophyta Cryptothallus mirabilis
Heterotrophic Anthophyta Burmannia (Burmanniaceae) Petrosavia (Petrosaviaceae) Arachnitis (Corsiaceae) Cotylanthera (Gentianaceae) Monotropa (Pyrolaceae) Aphyllorchis (Orchidaceae) Pterospora (Ericaceae) Geosiris (Iridaceae) Lacandonia (Triurdiaceae)
wisent = ♀ ox ♂ bison Verkaar, E.L.C., Nijman, I.J., Beeke, M., Hanekamp, E. & Lenstra, J.A. 2004 Maternal and Paternal Lineages in Cross-Breeding Bovine Species. Has Wisent a Hybrid Origin? Molecular Biology and Evolution21: 1165-1170
Paramecium (Oligohymenophora, Ciliophora) Contractile vacuole From: Barnes, R. D. 1980 Invertebrate zoology. Saunders Coll, Philadelphia Kozloff, E. N. 1990 Invertebrates Saunders Coll, Philadelphia Patterson, D. J. 1992 Free-living freshwater protozoa. Wiley & Sons, NY
mitosis MT = micro-tubercule
Mitosis - Meiosis Gametes mitosis meiosis
Ames test Liver extract is added, because the enzymes can transform compounds The metabolites can have a different mutagenicity This makes the test more relevant for mammals (humans) Ames produced mutants of Salmonella typhimurium that cannot synthesize histidine The medium has all required nutrients, but only enough histidine for some 4 divisions Only if back-mutation occurs during growth can colonies continue to grow and be counted The inoculum size is 108. Genome size is 4.85 Mbp. What is the expected survival probability in case of 100 revertant colonies? We expect 4.85 mutations per genome in the case of random mutations and so high mortality The survival probability turns out to be typically 100 %, so back-mutation is not random
Cells, individuals, colonies 2.5 vague boundaries • plasmodesmata connect cytoplasm;cells form a symplast: plants • pits and large pores connect cytoplasm: fungi, rhodophytes • multinucleated cells occur; individuals can be unicellular: • fungi, Eumycetozoa, Myxozoa, ciliates, Xenophyophores, Actinophryids, Biomyxa, diplomonads, • Gymnosphaerida, haplosporids, Microsporidia, nephridiophagids, Nucleariidae, plasmodiophorids, • Pseudospora, Xanthophyta (e.g. Vaucheria), most classes of Chlorophyta (Chlorophyceae, Ulvophyceae, • Charophyceae (in mature cells) and all Cladophoryceae, Bryopsidophyceae and Dasycladophyceae)) • cells inside cells: Paramyxea • uni- and multicellular stages: multicellular spores in unicellular myxozoa, gametes • individuals can remain connected after vegetative propagation: plants, corals, bryozoans • individuals in colonies can strongly interact and specialize for particular tasks: • syphonophorans, insects, mole rats Kooijman, Hengeveld 2005 The symbiontic nature of metabolic evolution. In: Reydon & Hemerik (eds) Current Themes in Theoretical Biology: A Dutch perspective. Springer, Dordrecht rotifer Conochilus hippocrepis Heterocephalus glaber
DEB tele course 2009 http://www.bio.vu.nl/thb/deb/ Free of financial costs; some 250 h effort investment Program for 2009: Feb/Mar general theory April 18-22 symposium in Brest Sept/Oct case studies & applications Target audience: PhD students We encourage participation in groups that organize local meetings weekly Software package DEBtool for Octave/ Matlab freely downloadable Slides of this presentation are downloadable from http://www.bio.vu.nl/thb/users/bas/lectures/ Cambridge Univ Press 2000 Audience: thank you for your attention