B2- T Brucei Intro

Question 1

WhT 2 types of Brunei are there

Answer 1

Gambiense and rhodesiense (zoonotic and chronic illness)

Question 2

What arthropod vector

Answer 2

Tsetse fly

Question 3

Which trypanosoma causes Chagas’ disease in South America

Answer 3

T cruzi

Question 4

Where does t brucei live

Answer 4

Ec eg in blood or csf

Question 5

Explain the life cycle from infection into human

Answer 5

Metacyclic form is injected from saliva which forms long and slender form with rapid binary fission

Then some switch to short and stumpy (not dividing) for transmission back to fly (more resistant)

Fly intakes short and stumpy and in gut will convert to pro cyclic form with binary fission which then travels to salivary glands and forms epimastigotes
sexually reproducing to make the metacyclic form taken up by humans

Question 6

Which disease does it cause which is lethal

Answer 6

African trypanosomiasis

Question 7

How do they survive since they induce a strong ab responses in blood

Answer 7

Evasion through changing surface coat happens every 7 days in random parasites

Question 8

Explain the waves of parasite Mia

Answer 8

Every 7 days there is a drop in the peak where ab / adaptive has kicked in

Then evasion occurs

Question 9

Which genus’s are closely related to t brucei (all kineroplastida)

Answer 9

Crithidia fasciculata - used because not parasitic

And leishmania

Question 10

Which type of brucei causes more chronic illness

Answer 10

Rhodesiese

Question 11

Since it’s diploid organism, how many chr pairs does it have e

Answer 11

11

Question 12

What other chr do they have

Answer 12

100 mini and 5 intermediate

Question 13

How many predicted vs specific genes

Answer 13

9000 fenes

1700 specific to them

Question 14

Is this big compared to bacteria

Answer 14

Yes 35mb vs 5mb

Question 15

Which rna pol 1 is usually for rrna but used for pcg like vsg in brucei

Answer 15

Rna pol 1

Question 16

Where are these genes on chr

Answer 16

Subtelomeric regions (close to ends)

Question 17

Why are most vsg pseudo genes (non functional eg with mutations in promoter)

Answer 17

Help to form mosaic genes by ectopic recombination

Question 18

Why would blood borne parasites need lower metabolic capacity

Answer 18

Large amounts in blood

Question 19

What % of all dna is kinetoppast

Answer 19

10-20%

Question 20

Where is kinetoplast located

Answer 20

Base of flagella

Question 21

What does compartmentalisation of nucleus mean

Answer 21

Diff compartments for replication of dna and also for transcription eg pol 1 activity in diff place to pol 2

Question 22

How does pol 2 localisation differ to 1 and 3

Answer 22

1 has 1localised spot in Extranucleolar body and nucleolus

2 has poles (appears in poles)

3 is scattered around nucleus

Question 23

What is the nuclelus for

Answer 23

Production of ribosomes
Pre rrna processing and 40/60s assembly

Question 24

Where are rrna genes and rna pol 1 located

Answer 24

On periphery of the nucleolus

Question 25

Which kinase needed for nucleolus organisation and what happens if disrupted

Answer 25

Tor1 kinase

If not there is dispersion of pol 1

Question 26

What types of chromatin are in brucei nucleolus

Answer 26

Eu and hetero (also packaged with dense chromatin histone octamers)

Question 27

How does chromatin differ to mammals

Answer 27

Loosely packed and chr don’t condense during mitosis

Question 28

Is condensation different between different forms

Answer 28

Yes different In procyclic (insect form) and the blood stream form

Question 29

Which proteins also contained at the periphery nucleolus

Answer 29

Nuclear function proteins

Like for rna pol 1 txn
Transcription EF (tfIIS)
NoLP proteins

Question 30

How are Hi-C and pacbio linked together to study brucei

Answer 30

Hi-c chromatin capture allows to capture interactions between dna in the tertiary structure far away in primary

Cross link/freeze dna via formaldehyde

RE cutting

Ligation

Amplification by PCR

Pacbio long read single dna RT sequencing (not fragments like illumina)

Question 31

What is the difference between the epimastigote forms and metacyclic

Answer 31

Metacyclic are infective

Question 32

Why is it called sleeping sickness

Answer 32

Can enter the csf gaining access to the brain and causing lethargy, confusion, seizures, paralysis / dearh

Question 33

In mammalian cells, our nuclei have chr territories where our chr will segregate in different areas of nucleus. Is this found in t brucei

Answer 33

No evidence yet