Fungal Cell Biology

Question 1

What % of all angiosperm plants form a mycorrhizal symbiosis with fungi?

Answer 1

95%

Question 2

What relation do 95% of angiosperms plants form with fungi?

Answer 2

Mycorrhizal symbiosis

Question 3

What do many fungi grow as?

Answer 3

Single-celled yeasts

Question 4

What are the forms of growth in fungal?

Answer 4

• Yeasts
• Hyphae
• Pseudohypha

Question 5

What are yeast cells?

Answer 5

Uni-cellular, often round

Question 6

What are hyphae cells?

Answer 6

Multi-cellular and elongated

Question 7

Do yeast and hyphae fungi grow similar or differently?

Answer 7

Differently

Question 8

Can fungi switch between morphological states?

Answer 8

Yes

Question 9

What can be useful for fungal to infect?

Answer 9

Dimorphisms

Question 10

How does dimorphism relate to pathogenicity of Candidia albicans?

Answer 10

Adhesion and colonisation:
-Yeast cell attach to cell surface
-Switch to hyphae 
Hyphal generation and invasion 
Vascular dissemination
-Switch back to yeast cells
-Swim around blood
Endothelial colonisation and penetration
-Switch back to hyphae
-Invade the tissue

Question 11

What does fungi switching between forms allow in host body?

Answer 11

Distribution around the body

Question 12

What are he two major growths of fungi?

Answer 12

• Yeast cells

- Hyphae

Question 13

Where are enzymes that support growth?

Answer 13

Growth region

Question 14

What are types of enzymes that support growth of fungi?

Answer 14

• Chitin synthase (Mcs1)

- Plasma membrane (Sso1)

Question 15

What is pseudohyphae growth of a fungi?

Answer 15

• Elongate
• Pear-like string of yeast cells
• Don’t separate

Question 16

How do vesicles reach growth region?

Answer 16

Via actin and microtubules

Question 17

What do fungal require to be delivered to growth region for fungal growth?

Answer 17

Vesicles

Question 18

Does yeast-cells require actin or microtubule for delivery of vesicles to growth region?

Answer 18

Actin

Question 19

Does hyphae cells require actin or microtubules for delivery of vesicles to growth region?

Answer 19

Short and long actin

Long microtubules

Question 20

Describe the cytoskeleton in budding yeast:

Answer 20

• Actin-patches (concentrated at budding)

- Actin-cables (delivers vesicles to growth region where they fuse with plasma membrane)

Question 21

Describe the cytoskeleton in hyphae:

Answer 21

• Long microtubules (support range of transport and arrange of protofilaments, providing bending-resistance)
• Long F-actin (not as straight)
• Actin patches (concentrated at the tip)

Question 22

What do fungal motors support along the cytoskeleton?

Answer 22

Motility

Question 23

What fungal motors do fungi contain to aid motility along the cytoskeleton?

Answer 23

• 10 classes of kinesins
• 1 type of dynein
• 4 classes of myosin

Question 24

Which end of the microtubule do dynein transport materials to?

Answer 24

Negative end

Question 25

Which end of the microtubule do kinesis transport materials to?

Answer 25

Positive end

Question 26

What does microtubules in hyphae allow?

Answer 26

Long-range of transport

Question 27

What is an apical body involved in?

Answer 27

Hyphae growth

Question 28

What is another name for apical body?

Answer 28

Spitzenkorper

Question 29

What do Spitzenkorper consist of?

Answer 29

Vesicles

Question 30

What do Spitzenkorper serve as?

Answer 30

Vesicle supply centre

Question 31

What does Spitzenkorper enable?

Answer 31

Polarised growth

Question 32

Why is polarised growth required?

Answer 32

To reach food supply and colonise substrate

Question 33

How do Spitzenkorper serve as a vesicle supply centre?

Answer 33

- Transport of vesicle along the cytoskeleton - Storage of vesicles in the Spitzenkorper - Release and fusion with plasma membrane

Question 34

What do Spitzenkorper contain?

Answer 34

- Secretory vesicles | - Endocytotic recycling vesicles

Question 35

What determines hyphae growth?

Answer 35

Rate of vesicle release and motility of Spitzenkorper

Question 36

What is a problem of multi-cellularity in hyphae cell?

Answer 36

If one dies, they all dies

Question 37

What solves the hyphae cell problem of 'if one dies, they all dies'?

Answer 37

Woronin bodies

Question 38

What do Woronin bodies do?

Answer 38

Isolate damaged hyphal cells

Question 39

Where are Woronin bodies concentrated?

Answer 39

Around septal pore

Question 40

What do Woronin bodies self-assemble into?

Answer 40

Crystalline assembly

Question 41

What are Woronin bodies?

Answer 41

Peroxisome-derived organelles that contain crystals of self-assembled Hex1 protein

Question 42

What are fruiting bodies?

Answer 42

Mushrooms

Question 43

What doe mushrooms release for reproduction?

Answer 43

Fungal spores

Question 44

What is the organisation of basidiomycete?

Answer 44

- Caps - Gills - Basidia with spores

Question 45

What is a problem with basidiomycete reproduction?

Answer 45

Spores are deep in cap

Question 46

What is the mechanism of spore discharge in basidiomycete?

Answer 46

- Two water droplets are formed on surface spore due to secretory of mannitol and other hygroscopic sugars - Two water droplets = Adaxial drop and Bullers drop - Bullers drop increases in size due to recruitment of atmospheric water - Fusion of drops cause sudden change of centre of gravity creating a propulsive force - Release of spore - Wind takes it away

Question 47

What is the discharge distance of a basidiomycete spore?

Answer 47

Few millimeter

Question 48

How many spores are released from a single mushroom per second?

Answer 48

3000

Question 49

How do ascomycete fungi release their spores?

Answer 49

- Perithecium contain ascus which holds spore - Internal pressure building --> turgor pressure up to 100-700kPa - Cell upon up at the tip and shoots the spore out

Question 50

How do mold fungi release massive numbers of spore into the air?

Answer 50

Wind/touch

Question 51

Which causes the action of basidiomycete distribution?

Answer 51

Rain splash