Fig a Green algae Amoebozoans Opisthokonts Alveolate s Stramenopiles Diplomonads Parabasalids Euglenozoans Dinoflagellates Apicomplexan s Ciliates Diatoms Golden algae Brown algae Oomycetes Excavata Chromalveolata Rhizaria Chlorarachniophytes Forams Radiolarians Archaeplastida Red algae Chlorophytes Charophyceans Land plants Unikonta Slime molds Gymnamoebas Entamoebas Nucleariids Fungi Choanoflagellates Animals (Plantae) the 5 supergroups

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Concept 28.6: Unikonts include protists that are closely related to fungi and animals The supergroup Unikonta includes animals, fungi, and some protists This group includes two clades: the amoebozoans and the opisthokonts (animals, fungi, and related protists)

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fig. 28-UN5 Amoebozoans Nucleariids Fungi Choanoflagellates Animals Unikonta Excavata Chromalveolata Rhizaria Archaeplastida

Fig Common ancestor of all eukaryotes DHFR-TS gene fusion Unikonta Excavata Chromalveolata Rhizaria Archaeplastida Choanoflagellates Animals Fungi Amoebozoans Diplomonads Euglenozoans Alveolates Stramenopiles Rhizarians Red algae Green algae Plants RESULTS Stechman and Smith, 2002

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Amoebozoans Amoebozoans are amoeba that have lobe- or tube-shaped, rather than threadlike, pseudopodia They include gymnamoebas, entamoebas, and slime molds

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Slime Molds Slime molds, or mycetozoans, were once thought to be fungi Molecular systematics places slime molds in the clade Amoebozoa

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Plasmodial Slime Molds Many species of plasmodial slime molds are brightly pigmented, usually yellow or orange Video: Plasmodial Slime Mold Streaming Video: Plasmodial Slime Mold Streaming Video: Plasmodial Slime Mold Video: Plasmodial Slime Mold

Plasmodial “sporangia”

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings At one point in the life cycle, plasmodial slime molds form a mass called a plasmodium (not to be confused with malarial Plasmodium) The plasmodium is undivided by membranes and contains many diploid nuclei It extends pseudopodia through decomposing material, engulfing food by phagocytosis

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Cellular Slime Molds Cellular slime molds form multicellular aggregates in which cells are separated by their membranes Cells feed individually, but can aggregate to form a fruiting body! Dictyostelium discoideum is an experimental model for studying the evolution of multicellularity

Fig Spores (n) Emerging amoeba (n) Solitary amoebas (feeding stage) (n) Aggregated amoebas Migrating aggregate Fruiting bodies (n) ASEXUAL REPRODUCTION 600 µm 200 µm Key Haploid (n) Diploid (2n)

Fig Spores (n) Emerging amoeba (n) Solitary amoebas (feeding stage) (n) Aggregated amoebas Migrating aggregate Fruiting bodies (n) ASEXUAL REPRODUCTION 600 µm 200 µm Key Haploid (n) Diploid (2n) Amoebas (n) Zygote (2n) SEXUAL REPRODUCTION MEIOSIS FERTILIZATION

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Gymnamoebas Gymnamoebas are common unicellular amoebozoans in soil as well as freshwater and marine environments Most gymnamoebas are heterotrophic and actively seek and consume bacteria and other protists Video: Amoeba Pseudopodia Video: Amoeba Pseudopodia Video: Amoeba Video: Amoeba

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Problem Amoebas Entamoebas are parasites of vertebrates and some invertebrates Entamoeba histolytica causes amebic dysentery in humans Acanthamoeba Water born eye pathogen - contact wearers beware! (spiny)

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Opisthokonts Opisthokonts include animals, fungi, and several groups of protists

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Choanoflagellates Animals Fungi Gymnamoebas Entamoebas Nucleariids Unikonta Slime molds Amoebozoans Opisthokonts