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Nucleomorph Genome

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Nucleomorph Genome Nucleomorph Genome http://tolweb.org/Cryptomonads/2396 Crypt of the cryptophytes V – Vestibulum (vestíbulo) F – Furrow (sulco) G – Gullet (garganta) Brett et al. (1994) Protoplasma 181, 106. Types of periplasts Brett et al. (1994) Protoplasma 181, 106. Features of the cryptophytes • Biflagellated cells • Live in marine and freshwater habitats • Survive at low light levels • They have phycobiliproteins • Great importance in the food chain • They have chloroplasts with 4 membranes • They have a crypt that is structurally supported by a periplast • They have chlorophyll c2 instead of chlorophyll b • They do not have allophycocyanin • Periplastidial starch • Thylakoids grouped in pairs Cryptophytes vs. Chloraracniophytes Chlorarachniophyta Cryptophyta Photosynthetic pigments: Photosynthetic pigments: chlorophyll a and chlorophyll b chlorophyll a and c2 as well as other pigments evolutionarily related to phycoerythrins Do not have phycobilissomes Biliproteins within the thylakoid or biliproteins lumen; thylakoids grouped in pairs Uniflagellar ameboid cells with 2 flagella inserted near a crypt filamentous pseudopodia and asymmetric ellipsoidal cells Starch in cytoplasmic vesicles Periplastic starch (between the plastid envelope and the two outer membranes) Chloroplast surrounded by 4 Chloroplast surrounded by 4 membranes membranes ER not associated with the ER associated with the chloroplast chloroplast http://www.laborjournal.de/blog/?p=5529 Lineage Stramenopiles http://tolweb.org/Eukaryotes/3 Lineage Heterokonts Lineage Heterokonts • Heterokonts ≈ Stramenopiles • Biflagellated eukaryotic cells • Previous flagellum with mastigonemes (tripartite tubular hairs) • Hairless posterior flagellum • Chloroplasts surrounded by 4 membranes (photoautotrophic sub-lineage: Ochrophyta ≈ Heterokontophyta) • However, there are cells that have lost one or more flagella Lineage Heterokonts • Diatoms (> 100,000 species) • Brown seaweeds (Phaeophyceae) • Chrysophytes (golden algae) • Pseudofungi: Oomycetes (heterotrophic sub-lineage) • etc... Lineage Heterokonts Riisberg et al. (2009) Nannochloropsis • eustigmatophyte (not a green alga) • small size • spherical morphology • do not have chlorophyll b or c • rich in EPA • oleaginous species Lineage Heterokonts Riisberg et al. (2009) Diatoms (Bacillariophyceae) n Microalgae with valves of pectinous material impregnated with silicates Diatoms (Bacillariophyceae) n Pennatae n Centricae http://researcharchive.calacademy.org/research/diatoms/index.html Diatoms (Bacillariophyceae) n Unicellular; n Photoautotrophic, heterotrophic, symbionts; n Exoskeleton with silicates; n Essential in the marine trophic chain; n Contribute to 45% of the primary ocean productivity and 20% of global productivity Diatoms (Bacillariophyceae) http://researcharchive.calacademy.org/research/diatoms/index.html Diatoms (Bacillariophyceae) Diatoms (Bacillariophyceae) Fig.6 – Adapted representation of the frustules formation [8]. A) Internal illustration of a diatom, silica in-take via SIT proteins and polymerization in SDV. B) Frustule formation in SDV, fusion of SDV membrane with plasma membrane and exocytosis of newly formed exoskeleton. Lineage Heterokonts Riisberg et al. (2009) Heterotrophic Heterokonts: Pseudofungi Class Oomycetes Phytophthora infestans Mildew (lettuce) Mildew (potato) Phytophthora infestans Laminarina (β-1,3-glucano com ligações β-1,6) • Similar to fungi: hypha-like structures • They are diploid: the true fungal hyphae are haploid • Cell wall: essentially composed of cellulose instead of chitin • Reserve polysaccharide: laminarin (β-1,3-glucan with β-1,6 linkages).
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