Mosq. malaria interactions

Question 1

probing

Answer 1

look for good place- insert styets into skin - saliva out one tube and blood up another

Question 2

imbibing

Answer 2

sucking up blood
sift out plasma before remove stylet
break blood vessel and drink from pool of blood next to it

Question 3

prediaresis

Answer 3

Only Anopheles does this
remove the fluid from blood meal and liquid comes out of anus
80% of protein in bloodmeal is in blood cells

Question 4

Withdrawal

Answer 4

bloodfeeding dangerous, may need to withdraw and return and feed again before producing eggs

Question 5

female salivary gland

Answer 5

3 lobes - 1 median lobe, 2 lateral lobes
Distal region - produces apyrase in females - enables females to keep bloodfeeding - stops bloodvessels from blocking
Parasite only lives in distal region of slaivary glands

Question 6

crop

Answer 6

storage of sugar, in thorax

Question 7

sucking blood

Answer 7

suck from a pool of blood so no pressure from blood vessels

mosq create own pressure with pharangeal pumps

Question 8

After bloodfeeding

Answer 8

The single layered midgut epithelium is surrounded by
the basal lamina (basal matrix)
The apical cell membrane of the columnar cells is
extended into microvilli coated by a glycocalyx.
Enzymes secreted in response to a bloodmeal include
trypsins, chymotrypsin, aminopeptidase and
carboxylase

Question 9

Peritrophic matrix

Answer 9

Formed around the bloodmeal 12-24 hrs
when digestion complete haematin excreted with PM
Blood initiates gonotrophic cycle

Question 10

Vitellogenesis

Answer 10

Vitellogenin (yolk) is synthesised in the
fat body trophocytes as a precursor
molecule
It is a glycolipoprotein
secreted and carried in haemolymph to the ovaries where taken up as vitellin

Question 11

Structure of ovarian

Answer 11

Ovarioles contain follicles with an oocyte and nurse cells and
surrounded by an epithelium
every follicle develops synchronosly
if don’‘t finish bloodmeal some follicles will stop development or may be reabsorbed

Question 12

Follicles

Answer 12

Follicles arise from a germarium (and are connected to it by a
follicular stalk)
• The secondary follicle is resting
• The primary follicle undergoes development after a bloodmeal

Question 13

Incorporation of vitagellin into ovary

Answer 13

Vitellogenin passes between the cells of the follicular epithelium,
which are patent (have spaces), to the oolemma
•Vg is taken up by receptor mediated endocytosis and fuses with yolk bodies to become crystalline vitellin
•Vitellogenin carboxypeptidase is also secreted in the fat body
and selectively endocytosed
• Egg batch size is dependent upon bloodmeal size

Question 14

parasite affect persistance

Answer 14

if female doesn’t finish blood meal will come back for more
if oocysts present - more mosq give up early
if sporozoite present - more persistant and risky

Question 15

parasite affect probing

Answer 15

when sporosoites present will probe more often on multiple people
production of apyrase reduces if salivary infection - means blood will dry up so have to probe more

Question 16

Interaction inside midgut

Answer 16

parasite needs to get past barrier of midgut cells
Penetrates cell through midgut traversal
stays under basal lamina
cells that parasite passes through die via apoptosis and shed from basal lamina

Question 17

Time bomb theory

Answer 17

cells produce peroxidases which degrade proteins in the cell.
if parasite hasn’t traversed to the next cell in time it will get stuck in the cell

Question 18

effects of nitric oxide

Answer 18

Nitric oxide produce apoptosis
nitric oxide is a trigger for apoptosis in the parasite too
production of nitric oxide is an immune response to kill parasites in the midgut
during apoptosis chromatin condenses

Question 19

parasite affect on egg production

Answer 19

costly and does not benefit the parasite
infected mosq. don’t produce as many eggs
reduction of resources put into eggs
less protein in fat body but more in the haemolymph - because it was not being taken up by the ovaries

Question 20

Fecundity

Answer 20

no of eggs produced

Question 21

Fertility

Answer 21

no of eggs that hatch

Question 22

apoptosis in ovraies

Answer 22

used caspase inibitors - showed that apoptosis of follicles happens first then reapsorption

Question 23

GPI

Answer 23

plasmodium manipulator molecule shed in red blood cells in gut
produced by ookinetes
initiates immune response which affects production of eggs

Question 24

parasite affect on sugar feeding

Answer 24

expression of insulin like peptides elevated

glycogen levels higher in infected mosquitoes

Question 25

Insulin like growth factor (IIS)

Answer 25

The insulin signalling cascade plays a critical role in
regulating the immune response and stress responses
in both mammals and invertebrates
In mosquitoes the IIS regulates; reproduction,
lifespan, metabolism and pathogen resistance