Protozoans

Protozoan Groups

Ciliates

Amebas

Apicomplexans

Flagellates

Newly Revised Protozoan Taxonomy

• Clade Viridiplantae– Phylum Chlorophyta

• algae with chlorophyll

– Phylum Euglenozoa• euglenoidea

• kinetoplasta

• Clade Retortamonada– no mitochondria

• Clade or Superphylum Alveolata– Phylum Apicomplexa

– Phylum Ciliophora

– Phylum Dinoflagellata

• Amebas

Basis of Taxonomy

• Morphological traits– Flagella

– Cilia

– Pseudopodia

– Shells (tests)

• Reproductive modes– Sexual

– Asexual

– Spore formation• Distinct reproductive cell

forms

– Cyst formation

• Characteristic organelles– Apical complex

– Kinetoplast

– mitochondria

– plastids

• Trophism– Heterotrophic

– Autotrophic

• Molecular – DNA sequences

– gene sets

Symbiotic Relationships

• Host

• Symbiont

• Relationship– Parasitism

– Commensalism

– Mutualism

Flagella & Cilia

• Axoneme

• Kinetosome

Fig. 11.6b

Pseudopodial Movement

Amoeba

• Amoeboid movement– Pseudopodial extension

• Phagocytosis– Engulfment of large particles

Contractile Vacuoles

• Osmotic regulation

– Remove excess metabolic H2O, and HCO3

– Remove H2O that enters by osmosis

Feeding

Examples of Binary Fission – Asexual Reproduction

Sexual Reproduction

• Conjugation– Meiotic nuclear division

– Transfer of portion of genome between partners

• Sporogomy– Formation of sporozoites

– Formation of gametocytes from sporozoites

– Fusion of gametocytes to form new generation of sporozoite

– Gametocytes and sporozoites are present in separate hosts

Cyst Formation

Euglenozoa

• A phytoflagellate– Autotrophic

– Opportunistic heterotroph

Free Living Flagellates

Pandorina colony

Colonial Flagellates

Volvox colony

Cell Specialization in the Colonial Volvacae

Examples of Ameba Body Forms

Naegleria fowleri

Foraminiferan Tests

Radiolarian Undergoing Binary Fission

Dinoflagellates

Flagellates

• Parasitic examples

• Cyst formers

Intracellular Parasitic Flagellates

Parasitic Kinetoplastids

• Phylum Euglenozoa– Subphylum Kinetoplasta

• Class Trypanosomatidea– Trypanosoma spp

– Leishmania spp

Trypanosomiasis

• African sleeping sickness – Eastern hemisphere– Trypanosoma brucei

– Vector – Tsetse Fly - Glossina spp

Immages from links at http://www.biosci.ohio-state.edu/~parasite

Trypanosomiasis

• Chaga’s disease – Western hemisphere– Trypanosoma cruzi

– Vector – assassin bug – Rhodnius spp, Panstrongylus spp and Triatoma spp

Life Cycle of Trypanosoma

• http://www.genomics.liv.ac.uk/tryps/trypsmovie.html

Leishmaniasis• Leishmania spp

• Vector – sandfly – OW Phlebotomus spp, NW Lutzomyia, Brumptomyia

• Similar protozoan to Trypanosoma sp

• Cutaneous and visceral forms of disease

Life Cycle of Leishmania

Taxonomy of Apicomplexans

• Phylum Apicomplexa– Class Coccidiea

• Plasmodium spp , Toxoplasma spp

• Life cycle with multiple hosts

– Class Gregarinea• Gregarines – invertebrate parasites

• Single host life cycles

Apical Organelles of the Apicomplexans

Life Cycle of Plasmodium vivax

Anopheles spp

Phylum Ciliophora

Tetrahymena

Stentor

Vorticella

A Ciliate – Parmecium sp

Reproduction in CiliatesConjugation Fission

Conjugating Tetrahymena

Conjugation

Conjugation

Conjugation

derived from the micronucleus.

Reproduction in Ciliates – Sexual and Asexual

Fission = asexual

Vorticella

http://youtu.be/rqD3m9hHhlo

http://youtu.be/pds8w7C9FEw