1. Kingdom Protista Sometimes called the “Junk drawer”
Contains animal-like, plant-like and fungus-like organisms
Plankton (zoo-/phyto-/myco)

2. CHARACTERISTICS OF PROTOZOANS
Unicellular
Eukaryotic
Basically Ingestive Heterotrophs
Lack cell walls but have definite shapes
Most are motile
Basically reproduce by asexual reproduction
Aerobic but some can live in anaerobic conditions (ones living in digestive tracts)

3. Special structures: Macronucleus – controls metabolism
Micronucleus - involved in conjugation
Contractile vacuoles – maintains
Meostasis
Ingestion structures
Anal pore – excretion of wastes
Trichocysts – defense mechanism

4. HABITAT Majority of free-living Marine, terrestrial & freshwater.
Some are parasites on algae to vertebrates
Make up the zooplankton in marine ecosystems. Feed on phytoplankton
Abundant in soil or on plants & animals
Some live in guts of termites, roaches & ruminants (cows)

5. DIFFERENT PROTOZOANS Paramecium with trichocysts Paramecium Didinium
Vorticella
Stenor

7. PARAMECIUM Paramecium is a small unicellular organism.
It is plentiful in freshwater ponds.

8. STRUCTURE

9. Position Of Protists In The Prokaryotic Kingdom

11. Classification Mastigophora – have one or more flagella
Classified by method of locomotion
Mastigophora – have one or more flagella
- Have a flagella with a 9-2 microtubule arrangement
- Flagella are polar & undulates, pushing protozoan in opposite direction
- Longitudinal reproduction
i.e. Peranema,
Chilomonas

12. Ciliata (Ciliophora) - Have cilia.
- Similar in structure to flagella but shorter and all over surface of organisms
- Cilia usually arranged in rows & connected to each other
- Cilia near oral cavity involved w/ food getting
- Transverse fission, & sexual repro by conjugation
Ie – Paramecium, Didinium, Blepharisma,
Vorticella, Stentor

13. Sarcodina
- Use Pseudopods for movement
- Cytoplasmic streaming – amoeboid movement
- Tips of pseudopods are less viscous so flow goes in that direction
- Pseudopods for phagocytosis
- Reproduce by binary fission
i.e. Amoeba, Naegleria, Heliozoans, Radiolarians, Foraminifera

14. Sporozoa No method of motility
All are parasites – use host for motility
Reproduce by schizogamy (multiple fission) in host & sexual reproduction in a second host
Ie. Plasmodium (malaria), Giardia, Toxoplasma,
Trypanosoma, Trichomonas

15. Animal-Like Protists

16. PROTOZOAN PROTIST

17. EVOLUTION Evolved from the Archae approx. 1.5 billion years ago
Polyphyletic group- protists arose by way of more than one ancestral group
Represents separate evolutionary lineages
Plant like b/c autotrophic (produce their own food)
Animal-Like b/c they are heterotrophic (feed upon other organisms)

18. Figure 8.20

19. TYPES OF PROTOZOANS Zooflagellated Protozoans Flagellated Protozoans
Phytoflagellated Protozoans

20. Zooflagellated Protozoa
Lack chloroplast
Heterotrophic
Some members are important human parasites
Species Trypanosoma brucei cause African sleeping sickness (Intermediate host- Tsetse flies )

21. Figure 8.8 (b)

22. Flagellated Protozoa
Flagellates are the ancestors of ameoboid protozoan
Phytoflagellated (photosynthesizing)
Zooflagellated (particle feeding and parasitic)

23. pellicle
contractile
vacuole
macronucleus
cytoplasm:
ectoplasm
endoplasm
micronucleus
cilia
oral groove
anal pore
gullet
food
vacuole

24. Phytoflagellated Protozoa
Chlorophyll (oxygen for marine life)
One or two flagella
These protozoans are large portion of the marine food i.e dinoflagellates
Two flagellates, chlorophyll, xanthophyll (bloom=red tides) and results in fill kills (Red sea, bible)

25. Figure 8.6

26. Other Phytoflagellated Protozoa Euglena
Freshwater phytoflagellated protozoa
Chloroplast has a pyrenoid (synthesizes and stores carbohydrates)
Feed by absorption or are heterotrophic
Stigma- photoreceptor at the base of the flagellum
Haploid organisms and reproduce binary fission

27. FUNGUS LIKE PROTISTS
Like fungi, they are heterotrophs, have cell walls, use spores to reproduce. Unlike fungi, they can move at some points in their life cycle.
Three types:
- Water Molds and Downy Mildews:
Both types live in water or moist places, & look like fuzzy threads.
They attack food crops (potatoes)
- Slime Moulds: Live in moist soil and on decaying plants and trees. Some are with beautiful colors. They move using
pseudopods.
They eat bacteria and other microorganisms. Can combine, forming a multicellular mass & spores. Spores develop into a new generations of slime moulds

28. PLANT LIKE PROTISTS
Called algae & are autotrophs (pigments & photosynthesis).
* Some are unicellular, living unconnected from other algae cells.
* Others form colonies together with a few cells specializing for reproduction, etc. (Most colony cells continue to carry out all normal functions.) * Some algae are multicellular like seaweed, where all cells are specialized.

29. Paramecium Movement
The outer surface of the cell is covered with many hundreds of tiny hair-like structures called cilia.
These act like microscopic oars to push through the water, enabling the organism to swim.
If Paramecium comes across an obstacle, it stops, reverses the beating of the cilia, swims backwards, turns through an angle and moves forward again on a slightly different course.
It moves so quickly that we have to add a thickening agent or quieting solution to the slide to slow it down to study it.

30. Paramecium Feeding
Paramecium has a permanent feeding mechanism, consisting of an oral groove and a funnel-shaped gullet into which food is drawn by the combined action of cilia which cover the body and other cilia lining the oral groove and the gullet.
As it moves through the water it rotates on its axis and small particles of debris and food are collected and swept into the gullet.
They feed on small organisms such as bacteria, yeasts, algae and even other smaller protozoa.

31. Paramecium Excretion
Food waste left in a food vacuole is excreted through the anal pore (the vacuole and pore fuse.
Other wastes left over from cellular activity (metabolic waste) simply diffuse through the pellicle.
Excess water and some metabolic wastes are excreted through the contractile vacuole.

32. ASEXUAL REPRODUCTION IN PROTOZOANS

33. Asexual Reproduction in Protozoa

34. Conjugation in Paramecium

36. Paramecium Reproduction
In favourable conditions the cell divides in two by a process called binary fission (asexual reproduction).
This forms two new cells, each of which rapidly grows any new structures required and increases in size.
This whole process may take place two or three times a day if conditions were right.

37. Paramecium Reproduction
This is a more complicated method called conjugation (sexual reproduction).
It involves two cells coming together to exchange nuclear material.
The two cells then separate and continue to reproduce by simple division.
It is similar in some ways to sexual reproduction in more complex animals.

38. Reproduction in Ciliates
Paramecium conjugating
Transverse Binary
fission

39. Symbiotic lifestyles Symbiosis
Parasitism- a form of symbiosis- organism lives in or on other (Host)

40. Other kinds of symbiosis
Don’t harm host
Commensalisms- one member benefits
Mutualism- both benefit

41. Some parasites have life cycles involving multiple hosts
Definite host- harbors the sexual stages of the parasite
Intermediate host- the offspring enter another host where they reproduce asexually, to complete lifecycle the final asexual stage must have access to a Definite host

42. Paramecium Grammers Growth: 0.05 mm avg. Respond:
-react to chemicals – salt and vinegar
-live in slightly acidic environments (stagnant H2O)
-anterior end sensitive – move by trial and error

43. Paramecium continued…
Adaptations:
Cilia to help feed and escape
Contractile vacuoles
Trichocysts

44. Paramecium continued…
Movement: by cilia in circular motion, move ~ 60 mm/hr
Metabolism:
-food pulled into oral groove by cilia
-food vacuole forms at gullet
-lysosome aids with digestion
Feed mostly on bacteria, smaller protozoans and algae.

45. Paramecium continued…
Excretion:
-Contractile vacuole removes excess H20.
-C02 across pellicle by diffusion
-anal pore removes waste.
Reproduction: Asexual - cell division
Sexual – conjugation (exchange of micronucleus DNA)

46. CLADOGRAM OF PROTOZOA RELATIONSHIPS

47. .

48. Endosymbiosis and Cytoplasmic Inheritance in Paramecium

49. This Topic Will Focus On The Following :
Altenburg paper (1948)
Plasmagene hypothesis
Kappa body symbiosis
Current understanding
of Kappa bodies (Preer
1974)
Other cytoplasmic inheritance
in Paramecium (Meyer 2002)
Paramecium biology
Cell biology
Life cycle

50. Altenburg paper (1948) investigates the evidence that Kappa bodies are a symbiont
Kappa bodies are elements within Paramecium that cause them to be killers
Killer Paramecium kill other Paramecium in the immediate environment
Kappa particles, thought to be plasmagenes by Sonneborn, but Altenburg suggest they may be symbionts

51. The plasmagene theory suggested kappa bodies were genes within the cytoplasm
Plasmagenes defined as self-replicating structure capable of producing traits that exist in the cytoplasm and are independent of chromosomal genes.
The trait that Kappa bodies produce is the killing factor
Kappa bodies are inherited through the cytoplasm and not through chromosomes
Sonneborn wrote in 1976, “It was awful of me to be so attached to a pet idea. That was an ordeal between my mind and my heart and it took a while for the mind to win and the heart to accept. Impersonal scientific objectivity is a goal to be sought by hard self-discipline; we are not born with it.”

52. Altenburg’s evidence that Kappa bodies are symbionts is strongly supported by evidence
Preer (1948) showed Kappa is large enough to see under a light microscope
38o C kills Kappa but not Paramecium
Division of Kappa and Paramecium is independent of each other
Paramecium with symbiont
There is an upper limit of the number of Kappa in Paramecium
More likely a symbiont than a parasite

53. Preer (1974) reviewed the overwhelming evidence that Kappa bodies are symbionts
Kappa contains DNA, RNA, protein, and lipids in proportions expected in bacteria
Kappa contains electron transport system with cytochromes similar to bacteria and not eukaryotes
Electron micrograph of symbionts
Cytochrome
Glycolysis & Kreb Cycle
Electron microscopy clearly showed that Kappa is prokaryotic
Electron micrograph of flagellated Kappa

54. Current information has shown why Kappa induces killing and the different types of bacteria symbiosis
Kappa bodies kill other Paramecium by releasing toxins into the environment
The presence of the symbiont makes the host resistant to the toxin
Kappa bodies are transmitted by the cytoplasm during asexual division
Many other types of symbionts found
gamma
sigma
lambda
alpha
Kappa is the most common
delta pi
omega mu

55. The discovery of bacterial symbionts within Paramecium allows for their taxonomic classification
Kappa, mu, gamma, and nu are in genera Caedobacter
Alpha bodies are in the genera Cytophaga
Lambda and sigma are in genera Lyticum
Delta bodies are in genera Tectobacter

56. Differences have been found between Kappa bodies in the same host
Some Kappa bodies contain refractile ( R ) bodies
R body is a type of inclusion body
When genes from one organism are within another organism and are transcribed, a inactive protein may form
Magnified image of coiled R body (2)

57. Kappa bodies may contain ‘R’ bodies and it affects their reproductive capability
Non bright Kappa bodies do not contain R bodies but can reproduce
Bright Kappa bodies do contain R bodies but cannot reproduce
Dividing symbiont
Non bright produce other non bright, but occasionally a non bright turns into a bright
Toxicity associated only with Brights

58. There is still unsolved questions regarding Kappa body symbiosis
What benefit does Paramecium get from the symbiosis?
How does the presence of a Kappa body induce resistance to the toxin?
Resistance can be overcome with large toxin dose
The presence of Kappa with or without R bodies induces resistance to the toxin

59. Other types of cytoplasmic inheritance discovered in Paramecium and other ciliates is:
Genome-wide DNA rearrangements
Mating type
Serotypes

60. Paramecium has a complex cellular biology
Eukaryotic
Ciliates contain at least 2 nuclei
Germ-line micronucleus (MIC)
Somatic macronucleus (MAC)
MAC is generated from the MIC
Extensive genome rearrangements occur in the MAC
Diagram of Paramecium

61. The two nuclei make the life cycle of Paramecium more complicated than other eukaryotes
MIC goes through meiosis and the haploid MIC goes through mitosis
Result is 4 haploid MIC, but 2 are degraded
Paramecium exchange 1 haploid MIC
MIC fuse and form diploid MIC and duplicate via mitosis
Old MAC degrades and duplicated MIC is processed into new MAC
In asexual reproduction, the MIC goes through mitosis and the MAC goes through amitosis

62. Genome-wide rearrangements of the MAC genome consists of deletion of DNA sequences and chromosome amplification
The developing new MAC loses % of the genome depending on the ciliate
MAC chromosomes are amplified to a high ploidy level
Deletion occurs after an initial amplification of the MIC genome but before the ploidy level is reached

63. The deletion of DNA is located at specific sequences called internal excised sequences (IES)
IES are located in coding and non-coding regions of the MIC genome
These sequences are not present in the MAC genome
At some point in MAC development, the IES sequences are deleted

64. The mating type of Paramecium shows maternal inheritance
Conjugation of P. caudatum by Yanagi
Paramecium has 2 mating types - O and E
Both are not determined by genetic differences as they are both produced in homozygous wild-type strains
Mating type is the same through asexual reproduction but can change after sexual conjugation and MAC formation
After conjugation O cells mostly produce other O cells and E cells produce other E cells

65. Paramecium mating types do not follow the Mendelian segregation of alleles
Mendelian segregation of allelic pairs
Maternal inheritance of mating types

66. Mating types O and E depends on different states of MAC genome
Transferring E maternal MAC into O cell causes the progeny to become E
Transferring O MAC does not change E cells
O is the default mating type
E cell
O cell
E cell
Produces
Insert E MAC

67. This differential state of MAC is dependent on the presence of IES in the MAC
The mutation mTFE causes O cells to become E
This mutation affects the excision of an IES on the G gene
The G gene is a surface antigen and the failure of excision causes a nonfunctional protein to be translated
Functional - type O
excision
Mutational
retention
Nonfunctional - type E
MIC G gene
MAC G gene

68. Microinjection studies have shown that the presence of an IES sequence in the MAC inhibits the excision of its homologous IES in the MIC
O cells contain G gene in the MAC without its IES (IES-)
E cells contain the G gene in the MAC with its IES (IES+)
Injecting a plasmid of IES+ G gene into O cell’s MAC created the retention of the IES in the MAC of daughter cells
Injection of IES- plasmid did not induce excision
The presence of IES in the MAC causes the retention of the IES in subsequent generations after sexual conjugation

69. Microinjection of IES+ plasmid retains the IES in the MAC genome after autogamy

70. Meyer (2002) asked, “How can a sequence introduced in one nucleus affect the excision of the homologous sequence in another nucleus?”
Two models developed
Model 1: Sequence-specific protein factors are required for the excision of the IES in the developing MAC
The problem with this model is the large number of protein factors needed, about 50,000
Model 2: Sequence specificity is achieved by homologous nucleic acid (most likely RNA) that is transported from the maternal MAC to the developing MAC

71. Mochizuki (2004) explained the Scanning Model, a synthesis of Meyer’s model 1 and 2
Entire MIC genome is transcribed bi-directionally and forms dsRNA
dsRNA is cut up into smaller RNA called scn RNA
Scn RNA move to the old MAC and any matching homologous sequences are degraded
Scn RNA that were not degraded move to the developing MAC
These scn RNAs target homologous sequences which are deleted in an RNA i-like mechanism

72. Polymorphic lifestyles
Have different forms during their life cycle
May form cysts (vegetative cells) when adverse conditions exist. Cysts are not heat and chemically resistant.

73. SUMMARY
Paramecium has many instances of cytoplasmic and maternal inheritance
Paramecium
Kappa bodies are bacterial symbionts that produce a killing factor and they are inherited through the cytoplasm
IES excision and retention in the MAC is maternally inherited by
the genome present in the MAC
Electron micrograph of Kappa

74. Ecological importance
Members of the food chain – Primary or Secondary consumers
Consume soil bacteria & algae (1 paramecium can ingest 5 million bacteria/day
Involved in sewage disposal by metabolizing nutrients present to carbon dioxide & water

75. HARMS Cause disease in host organisms
Malaria – Plasmodium via mosquito
Toxoplasmosis – Toxoplasma
African Sleeping Sickness – Trypanosoma
via tsetse fly
Chagas – Toxoplasma
Vaginitis – Trichomonas
Giardiasis – Giardia
150 million people/year in world contract Malaria & 1.5 mill/year die of it.

76. FACTS ABOUT PARAMECIUM
“One scientist calculated that if all the
progeny of a single Paramecium
survived, assuming a division rate of
once a day, then after 113 days, the
mass of paramecia would equal the
volume of the Earth! “