HAT life cycle

Question 1

The tsetse fly takes a blood meal and ______ along with ____are injected from the salivary gland.

Answer 1

Metacyclic trypomastigotes

anticoagulants

Question 2

The injected metacyclic trypomastigotes ___ into _____

Answer 2

transform

blood stream form trypomastigotes

Question 3

Trigger for the transformation of metacyclic trypomastigotes to bloodstream form trypomastigotes?

Answer 3

unknown possibly temperature response to the increase temperature in the host

Question 4

Blood stream form trypomastigotes multiply by _____ in various body fluids initialyy the blood and lymph but given enough time will go ___

Answer 4

binary fission

cerebral spinal fluid

Question 5

Blood stream form trypomastigotes ____ into _____ the trigger is ___

Answer 5

differentiate
short stumpy trypomastigotes
unknown - stumpy induction factor expressed by parasite causes the differentiation, it is suggested that the blood stream form trypomastigotes are aware of the number of other parasites around them (density dependent response)

Question 6

Where are short stumpy trypomastigotes adapted for life? why?

Answer 6

insect

they do not divide in the human and are essentially an evolutionary dead end

Question 7

Tsetse fly takes a meal and ingests which form of parasite?

Answer 7

bloodstream form trypomastigote

short stumpy form trypomastigote

Question 8

What happens to the BSF trypomastigote in the insect?

Answer 8

in the midgut it dies

Question 9

What happens to the SS trypomastigote in the insect?

Answer 9

in the midgut the SS transforms into procyclic trypomastigote

Question 10

what is the trigger of the transformation of SS to procyclic trypomastigote?

Answer 10

temperature
citrate
cis-aconitate

Question 11

Procyclic trypomastigotes multiply by______ and colonise the insect ___

Answer 11

binary fission

gut

Question 12

What happens to the procyclic trypomastigotes after colonising the insect gut?

Answer 12

unsure how but they migrate to the salivary gland
2 contrasting ideas:
• The parasite can get back up through the digestive system and back into the salivary gland
• The procyclic form somehow can access the blood supply and use this to get into the salivary gland

Question 13

In the salivary gland the procyclic ____ to _____ and the trigger is ___

Answer 13

transform
epimastigotes
unknown

Question 14

The epimastigotes in the insect salivary gland attach to the ___ via ___

Answer 14

epithelium

flagellum

Question 15

Epimastigotes divide by ___

Answer 15

binary fission

Question 16

What else can occur in epimastigotes?

Answer 16

sexual reproduction, genetic exchange of material but this is not an essential process

Question 17

Epimastigotes ___ into _____ with an unknown trigger

Answer 17

transform

metacyclic trypomastigotes