Fungi Flashcards
What kind of eating do fungi do? How has this helped them?
- Absorptive heterotrophy (saprotrophic, mutualistic, or predatory)
- led to diversity of biochems and interactions with other orgonisms
What sorts of things are fungi found in?
yeast, alcohol, feul, drugs –> pennecillium = greenish mold in fruit +cheese –> penecillin
What sorts of diseases are caused by fungi?
Trichophyton rubrum --> athlete's foot wheat rust powdery mildew Candida albicans = yeastinfection/ thrush snake disease
spotted lanternfly
-fungi act as biocontrol agent to keep this pest at bay
- Fungi life cycle
- unique anatomical structures
- unicellular or multicellular?
- most are haploid or dikaryotic (n+n) for most of life with short diploid phase
- mlticellular ones are filamentous fith hyphae, making masses called mycelium –> organized = mushrooms–> unorganized = molds
- unicellular ones are yeasts and microsporidians
fungal cells
- glycogen used for carb storage
- cell walls are mainly chitin
fungal history
- earliest one in Cambrian: 544 mya
- earliest ascomycetes in Silurian: 440 mya
- earliest chytrids, zygomycetes, and basidiomycetes in Deconian: 400 mya
- PALEOZOIC RADIATION
fungal phylogeny
- sister to choanoflagellates and animals
- chytrids were earliest diverging fungal lineage
- fungi include microsporidians
Two types of hyphae
-septate or coenocytic
fungal reproduction
Asexual:
- spores are produced in different ways
- hyphae can break off parent and grow seperately
- budding in yeast
Sexual:
- rare/unknown in some groups
- sporic meiosis or zygotic meiosis
Naming
- mostly named based off reproductive structures (usually swimming gametes/spores)
- zygosporangia, basidia, asci
microsporidia
- size
- cellularity
- feeding habits
- motitlity
- other fun facts
- among smallest eukaryotic cell (1-40 nm)
- unicellular fungi with chitin walls
- obligate intracellular parasites of animals (including humans)
- no motility
- no mitochondria –> mitosome
- complex parasitic life cycle
Microsporidiosis
- infective form of microsporidia
- resistant, long living spore
- spore pokes out its polar tubule and infects cell
- injects infective sporoplasm into host thru the tubule
- sporoplasm multiplies thru merogony (binary fission) or schizogony (multiple fission)
- either free in cytoplasm or in parasitophorous vacuole
- microsporidia develop by sporogony into mature spores
- during sporogony, thick wall forms around spore, providing resistance to adverse environment conditions
- spores fill up host cell and then burst it to infect other cells
- affect a bunch of dif animals and are in GI of ppl (especially if immune compromised)
- some animals have it naturally and pass it on to ppl
chytrids
- where?
- cellularity
- reproductive structures
- feeding styles
- usually aquatic (soil, pond, stream)
- some unicellular; multicellular ones are simple and form coenocytic filaments or rhizoids
- flagelated gametes (sexual) and zoospores (asexual)
- some are parasitic on plants/aquatic animals; many are saprophytic
Allomyces
- chytrid
- alternation of gemerations life cycle with 2 morphologically similar phases: one haploid (gametophyte) and one diploid (sporophyte)
chytridiomycosis
- caused by batachochytrium dendrobatidis
- non-hyphal chitrid
- zoospores penetrate skin and form zoosporangia
- grow in diameter and complexity
- discharge papillae
- infected amphibians die w/in 2 weeks
- cap lost and zoospores escape thru skin
zygomycota
- where?
- hyphae?
- lifecycle type?
- reproduction?
- examples?
- mainly terrestrial –> some aquatic parasites
- coenocytic hyphae
- most of lifecycle is haploid
- asecual reproduction by spores in sporangia
- sexual spores are made in zygosporangium
- Rhizopus = black bread mold
- Pilobolus = dung fungus
rhizopus life cycle
(2n) Fertilization
- zygospore
(n) Meiosis
- sporangiophore releases spores
- spores germinate to produce new mycelium
- compatible gametangia meet
(n+n) Plasmogamy
-zygosporangium
(2n) Fertilization
Pilobus
- zygomycota
- sporangial ejection
- sporangiophores are phototacic–> they detect the direction of light and orient the sprangia toward light (blue light works best)
- sporangia are shot several m away
- adaptive significance –> fungi themselves aren’t photosynthetic
Glomeromycota
- arbuscular mycorrhizal fungi
- coenoctic hyphae –> asexual spore production –> no known sexual reproduction
- associate with roots of plants (80-90% of plants have these associations)
- fungi get fixed carbon and plants get nutrients (esp K)
Who does endomycorrhizal stuff and who does ectomycorrhizal stuff?
- glomeromycota does endo
- ascomycota and basidiomycota do ecto
Ascomycota hyphae
-Hyphae septate with woronin bodies (small spheres with pores)
Ascomycota asci
- contain ascospores
- naked asci is most primitiv
- derived forms make ascomata (fruiting bodies with asci)
- cleistothecial (circle)
- apothecial (unwound circle)
- perithecial (tear drop with open top)
- ascolocular (closed tear drop)
Ascomycota life cycle
ascospores grow into mating structures
- join to make n+n structure with n hyphae
- ascoma (fruiting structure) with n+n asci
- nuclei fuse
- meiosis happens
- mitosis happens –> 8 ascospores
conidia
-Usually ascomycota, but sometimes basidiomycota and zygomycota use it for asexual reproduction
Saccharomyces
- single celled fungi
- replicate thru budding (asexual)
- replicate through ascospores (sexual)
- dimorphic
- bakers yeast
Pathogenic ascomycetes
- candida = yeast infection
- geomyces = white nose syndrome (95% mortality)
- ophiostoma ulmi and bark beetle = dutch elm disease
- cryphonectria parasticia = chestnut blight
- cordyceps = zombies
- ophiocordyceps sinesis = parasitizes ghost moth larva –> used in medicine
- trichophyton = human dermatophytes
- ergot = in wheat rye and if eaten causes hallucinations (from LSD), stomach cramps, and burning limbs –> st anthony’s fire and salem witch
mushroom forming ascomycetes
morels and truffles
-edible and toxic muschroms look alike
basidiomycota (club fungi)
- phylogeny
- hyphae
- forms
- special structures
- sister to ascomycota
- prolonged dikaryotic stage
- septate hyphae
- conidial, yeast, mushroom, lichen, and mycorrhizal types
- basidiospores on basidium
- many produce clamps and dolipore septa –> unique
dolipore septum
hyphae are septate with pores –> more complex than ascomyota’s
clamps
maintain dikaryotic condition characteristic in many basidiomycota
basidiomycota life cycle
fruiting body has n+n parts
- those parts go thru karyogamy (fuse nuclei)
- Meiosis –> 4 basidiospores n
- -germinating basidiospores/primary mycelium
- plasmogamy (fusing membranes) n+n
- basidioma
- basidioma with basidiocarp housing n+n structures
basidiomycota plant pathogens
- bracket or shelf fungus = sign of widespread fungal infection –> some kill and then eat
- rusts and smuts = fungal diseases of plants –> complex life cycles involving plants and insects
- puccinia = wheat stem rust –> 2 hosts and several spore producing stages –> no clamps or muschrooms
hen of the woods
used in east asian medicine
basidiomycota human and animal pathogens
cryptococcus neoformans
- opportunistic infective agent
- forms polysaccride sheath in host cells
- lung infections –> can lead to meningitis and encephalitis
- common in immunocompromized ppl
Malassezia
-yeast that may be involved in pancreatic tumors
lichens
- mutualistic associations between mcobiont (fungi) and photosynthetic organisms (cyanobacteria or green algae)
- usually asco or basidio
- soredia = photosynthetic cells wrapped in hyphae that travel thru air to form new lichens
overview of fungi
• Sister to animals +
choanoflagellates clade
• Characterized by chitin cell
walls
• Basal groups include chytrids
(motile) and microsporidians
(parasitic)
• Zygomycetes coenocytic (like chytrids) and
characterized by production of a zygosporangium
• Glomeromycota similar to zygomycetes; asexual
• Most derived groups are the Dikarya (Ascomycota and
Basidiomycota) characterized by production of
dikaryons, cells that are dikaryotic (n+n) and give rise to
sexual spores
