Kinetoplastid Protozoans

Question 1

Kinetoplastid protozoans include?

Answer 1

Trypanosoma brucei
Trypanosoma cruzi
Leishmania

Question 2

Kinetoplastid protozoans move via?

Answer 2

Flagella

Question 3

Eukaryotic flagellum structure?

Answer 3

9+2 axoneme structure
9 microtubule pairs surrounding two central microtubules
Dynein motors cause the microtubules to slide past one another which causes the movement of the flagella

Question 4

Where is the basal body located?

Answer 4

At the base of the flagellum

Question 5

What is Trypanosoma cruzi also known as?

Answer 5

American trypanosome

Question 6

What is Trypanosoma brucei also known as?

Answer 6

African trypanosome

Question 7

Trypanosoma cruzi causes?

Answer 7

Chagas disease

Question 8

Trypanosoma cruzi is spread by?

Answer 8

Kissing/Triatomine bugs

Question 9

Trypanosoma brucei causes?

Answer 9

Sleeping sickness

Question 10

Trypanosoma brucei is spread by?

Answer 10

Tsetse flies

Question 11

Trypanosoma cruzi affects people in which part of the world?

Answer 11

Latin America

Question 12

Trypanosoma brucei affects people in which part of the world?

Answer 12

Central African, Congo

Question 13

Leishmania is spread by?

Answer 13

Sandflies

Question 14

Leishmania causes?

Answer 14

Leishmaniasis

Question 15

What is the flagellar pocket?

Answer 15

It is where the flagellum emerges
It is where endocytosis takes place
It is an invagination at the base of the flagellum
Many invariant surface receptors are located here as it is protected from the immune system, sheltered

Question 16

Trypanosoma brucei infects which cells?

Answer 16

It does not, it is extracellular

Question 17

Trypanosoma cruzi infects which cells?

Answer 17

Many different cell types

Question 18

Trypanosoma cruzi replicates where?

Answer 18

In the cytosol

Question 19

Which cells does Leishmania infect?

Answer 19

Macrophages

Question 20

What do all kinetoplastid protozoa contain?

Answer 20

kDNA

Kinetoplast DNA

Question 21

How many mitochondria are present in Kinetoplastid parasites?

Answer 21

Unlike most eukaryotic cells, kinetoplastid protozoa contain a single mitochondrion

Question 22

What is the structure of the kDNA?

Answer 22

When condensed forms a disk
Made up of many concatenated DNA circles
Made up of minicircles and maxicircles

Question 23

How large are the minicircles?

Answer 23

Around 1kb

Question 24

How large are the maxicircles?

Answer 24

Around 20kb

Question 25

What is the function of the minicircles?

Answer 25

Only known function is to produce gRNAs for RNA editing

Question 26

What is the function of the maxicircles?

Answer 26

Similar size to mtDNA Basically mtDNA Produce mitochondrial rRNAs, cytochrome b, cytochrome oxidase subunits etc...

Question 27

How does replication of minicircles occur?

Answer 27

1) Topoisomerase II releases minicircles from the central region of the disk. They are released from the disk into the kinetoflagellar zone (KFZ) 2) Migrate to the antipodal sites and replicate as they do so 3) Once the antipodal sites are reached they are attached to the network periphery adjacent to the antipodal sites via topoisomerase II

Question 28

The replicated minicircles contain?

Answer 28

A nick/gap

Question 29

What may be the function of the nick/gap?

Answer 29

To mark the minicircles as replicated, to ensure only a single round of replication occurs

Question 30

When is the kDNA replicated?

Answer 30

When the flagella replicate

Question 31

How is the replicated kDNA divided?

Answer 31

Attached to the basal body via filaments kDNA is replicated as the flagellar system is duplicated As the basal bodies move apart the kDNA is seperated

Question 32

The minicircles are added to a moving?

Answer 32

A moving kDNA disk

Question 33

Why is the kDNA disk moving?

Answer 33

To ensure equal distribution of replicated minicircles

Question 34

What is the movement like in T.brucei?

Answer 34

Oscillation

Question 35

What is the movement like in T.cruzi?

Answer 35

Spinning

Question 36

Chemicals to inhibit kDNA replication could include?

Answer 36

Topoisomerase inhibitors | Or drugs to bind DNA

Question 37

Why is RNA editing required?

Answer 37

As the genes of the maxicircles contain frameshift mutations

Question 38

RNA editing involves the addition of deletion of?

Answer 38

Uridines

Question 39

RNA editing is mediated by?

Answer 39

gRNAs produced by minicircles

Question 40

gRNAs contian?

Answer 40

A 5' anchor sequence which dictates the addition or deletion of uridines, a 3' poly-U tail