Origins of Eukaryotic Diversity

Eukaryotic Tree

Characteristics l Nucleus l Membrane-bound organelles l Ribosomes (80s) l Usually unicellular –some colonial –some multicellular l Protozoa –ingestive l Algae –autotrophic l Fungus-like –absorptive

Origin of Eukaryotes l Autogeneous l Endosymbiotic

Secondary Endosymbiosis

Phylogeny of Eukarya

Classific ation

Supergroup: Excavata l Cytoskeleton features l Excavated groove (some) l Modified mitochondria

Supergroup: Excavata Clade 2 : Diplomonads ex. Giardia (lack plastids, lack functional etc in mitochondria (mitostomes), two haploid nuclei, flagella)

Supergroup: Excavata Clade 2 : Parabasala ex. Trichimonas (lack plastids, reduced mitochondria (hydrogenosomes, undulating membranes and flagella)

Supergroup: Excavata Clade 2 : Euglenozoans l Move by flagella with spiral or crysalline rod l Disc-shaped Cristae

Supergroup: Excavata Clade 2 : Euglenozoans Clade 3 : Kinetoplastids ex. Trypanosoma (single large mitochondria with kinetoplast)

Supergroup: Excavata Clade 2 : Euglenozoans Clade 3 : Euglenids ex. Euglena (anterior pocket with flagella)

Supergroup: Chromalveolates l DNA Sequence Data l Secondary endosymbiosis of a red alga

Supergroup: Chromalveolates Clade 1 : Alveolates l DNA Similarities l Membrane bounded sacs (alveoli)

Supergroup: Chromalveolates Clade 1 :Alveolata Clade 2 : Dinoflagellates Causes Red Tide (2 flagella in grooves, xanthophyll)

Supergroup: Chromalveolates Clade 1 : Alveolata Clade 2 : Apicomplexans ex. Plasmodium (parasitic, apical structure)

Supergroup: Chromalveolates Clade 1 : Alveolata Clade 2 : Ciliates (cilia), Ex. Vorticella, paramecium Cilia, two distinct types of nuclei

Supergroup: Chromalveolates Clade 1 : Stramenopila l Have hair-like projections on flagella l Store food as laminarin (Photosynthetic)

Supergroup: Chromalveolates Clade 1 : Stramenopila Clade 2 :Diatoms overlapping silica test pigments: carotene, xanthophyll

Supergroup: Chromalveolates Clade 1 : Stramenopila Clade 2 : Chrysophyta ex. Golden Algae Typically bi-flagellated pigments: carotene, xanthophyll

Supergroup: Chromalveolates Clade 1 : Stramenopila Clade 2 : Brown Algae pigments: fucoxanthin cell wall: cellulose, algin

Supergroup: Chromalveolates Clade 1 : Stramenopila Clade 2 : Oomycota ex. Water mold pigments:none cell wall: cellulose, coenocytic hyphae

Supergroup: Rhizaria l Thin pseudopodia used for movement and feeding

Supergroup: Rhizaria Clade 2 :Cercozoans Amoeboid-shaped protist with thin pseudopodia Predators found in marine freshwater, and soil

Supergroup: Rhizaria Clade 2 : Forams (porous shells - calcium carbonate) Both marine and freshwater (found in sand or attached – also planktonic)

Supergroup: Rhizaria Clade 2 :Radiolarians (fused plates – silica with axopodia) Mostly Marine (usually planktonic)

Supergroup: Archaeplastida l DNA Sequences l Endosymbiosis of cyanobacterium

Supergroup: Archaeplastida Clade 2 : Red Algae

l Multicellular (most) l Pigment: phycoerythrin l Cell wall: cellulose l no flagellated stage in their life cycle –probably lost during their history l used to produce agar

Supergroup: Archaeplastida Clade 2 : Chlorophytes

l Mostly Freshwater –Some marine –Some terrestrial l Unicellular, Colonial, Multicellular l Pigments:Chlorophyll a, b, and carotenoids l Cell walls: Cellulose

Supergroup: Archaeplastida Clade 2 : Charophytes l Similar to higher plants in color (pigment: Chlorophyll A and B and carotenoids). They are the closest relatives of land plants.

Supergroup: Archaeplastida Clade 2 : Charophytes l Four distinctive traits that are shared with higher plants: 1. Rings of cellulose-synthesizing proteins 2. Peroxisome enzymes 3. Structure of flagellated sperm 4. Formation of a phragmoplast

Supergroup: Unikonts l Single flagella (in those that have one) l Lobed-or tube-shaped pseudopodia l Fusion of three genes

Supergroup: Unikonts Clade 1 : Amoebozoans l Used for movement and feeding l Classification –Slime Molds u Plasmoidial u Cellular –Gymnamoebas (broad pseudopods) –Entamoebas (parasitic)

Supergroup: Unikonts Clade 1 : Amoebozoans Clade 2 : The Slime Molds l Clade 3 : Plasmoidial l Coenocytic Hyphae l (feeding stage) single mass of cytoplasm with many nuclei –Diploid

Supergroup: Unikonts Clade 1 : Amoebozoans Clade 2 : The Slime Molds l Clade 3 : Cellular l (feed like individual amoebas) l Septate hyphae –aggregate to breed or during stress

Supergroup: Unikonts Clade 1 : Amoebozoans Clade 2 : Gymnamoebas ex. Amoebas

Supergroup: Unikonts Clade 1 : Amoebozoans Clade 2 : Entamoebas ex. Entamoeba histolytica

Supergroup: Unikonts Clade 1 : Opisthokonts l Unicellular and multicellular with ties to fungi and animals (DNA sequences) l Posterior location of flagellum l Classification –Nucleariids –Choanoflagellates

Supergroup: Unikonts Clade 1 : Opisthokonts Clade 2 : Nucleariids l Unicellular – lack distinctive characters l Contain a posterior flagella l Temporary pseudopods l Feed on algae and bacteria

Supergroup: Unikonts Clade 1 : Opisthokonts Clade 2 : Choanoflagellates l Unicellular or colonial l Most are suspension feeders