Download Sporothrix schenckii

Fungi
All multicellular fungi have hyphae = tubular growth in a substrate
(soil, you etc.)
Diagram of fungal cell, animal like interior, plant like cell wall.
Cell wall of fungi = inner plasma membrane, like animal cells.
Outer Chitin (unique) outer sugar
Figure 30.1 Fungi in Evolutionary Context
Synapomorphies that distinguish the fungi:
• Absorptive heterotrophy
• Chitin in cell walls
Figure 30.3 Yeasts Are Unicellular Fungi
Budding: mitosis followed by asymmetrical cell division.
Mushrooms, bracket fungi,
molds
Molds. Reproductive stalks that
produce spores
Start aquatic, move to land with cuticle, spores, etc.
Most of what we see
(mushroom, black on
mold) is the sporangia for
dispersal.
Life cycle – sexual, spores for dispersal, “diploid” sort of
30.3 How Do Fungal Life Cycles
Differ from One Another?
Many species lack a sexual
stage—now classified using DNA
sequencing.
Deuteromycetes or “Imperfect
Fungi”—polyphyletic group of
species that have not yet been
placed in any existing group.
25,000 species
Lichens = fungi (base) plus alga (photosynthesis)
Some important things about Fungi
• absorbtion of water for plants and distribution of nutrients between plants
• antibiotics from protective secretions
• human diseases: ringworm, valley fever, toe nail rot
• agricultural issues; potato blight, wheat rust. Problem of monocultures
• world wide loss of frogs.
Fungus aids in water
uptake
Fungus can form home to
Bacteria, which can fix
nitrogen.
Fungi associated with tree root
Can share nutrients between plant species – counteract dominance.
Tall grass prairie
Lots of plants – no
dominance
Fungi hyphae
between plants may
share nutrients –
offset dominance.
Penicillin on agar
Ambassador hotel, LA
Mushrooms growing in carpet; try soaking your carpet some time – see
what grows = spores are everywhere.
Fairy rings – fungus growing out from center,
culminating in mushrooms = spore producing bodies
ringworm
Cultured ringworm
Potato blight
Wheat rust
Valley fever
• Figure 2. Monthly
precipitation and valley
fever incidence, 19881998 (top) San Joaquin
Valley California, (bottom)
southeastern Arizona.
[more details]
SPOROTRICHOSIS (Sporothrix schenckii
Rose-grower’s disease = in soil, starts
with thorn prick – gets into lymph system
and spreads. Treatible with drugs.
Toe nail rot
“World wide” decrease in amphibia = frogs, toads? And salamanders?
Due to? A) climate change, b) parasites, c) fungi.
Climate change = moisture changes, temperature changes.
Amphibian problems: mutant frogs ; due to trematode infection
Frogs more readily eaten by birds – secondary host of trematode
As few as 12 trematode larvae, known as cercariae, can kill or deform a
single tadpole by burrowing into their limb regions and disrupting normal
leg development, he said. A single infected snail can produce more than
1,000 cercariae in one night. Frogs that become deformed rarely survive
long in the wild, he said.
Increased trematodes due to increases in nitrogen and phosphorus in
water + pollution
Fungal infection of frog skin = vacuoles contain sporangia – a water
borne primitive fungus =chytridiomycosis
Probably spread world wide by dirty boots!
Plus frogs more susceptable if climate warmer.
Fig. 3. A population pyramid to demonstrate the factors thought to heighten
the impact of chytridiomycosis in amphibian populations.