Fungi
Defining Fungi
Evolution and Clades
• The time of divergence between animals
and fungi is not specific, but most likely
arose from a single celled organism.
• Various Clades are recognized based on
molecular sequence data
• As with protists, not all fungi are grouped
in well-defined clades
Defined Clades
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Microsporidia
Blastocladiomycota
Neocallismastigomycota
Chytridiomycota
Glomeromycota
Basidiomycota
Ascomycota
The Hyphae
Variable Number of Nuclei
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Monokaryotic
Dikaryotic
Heterokaryotic
Homokaryotic
• The Nucleus is the reproductive unit, not
the cell in Fungi.
Differentiation
• Dikaryon Stage (1n+1n vs. 2n)
• Reproductive Structures
• Spores
Microsporidia
Unicellular Parasites
Microsporidia
• Unicellular
• Obligate, intracellular,
animal pathogens
• Like mitochondria
• Commonly found in
immune deficient
patient.
Chytridiomycota and Relatives
Fungi with Flagellated Zoospores
Chytridiomycota
• Aquatic
• Flagellated
• Closely related to
ancestral fungal
form.
Blastocladiomycota
• Single Flagellum
• Haplodiplotonic
Lifecycle
• Possess a giant
mitochondrion in
Zoospore stage.
Neocallimastigomycota
• Digest Cellulose and
Lignin
• Found in Ruminants
• Anaerobic, with
greatly reduced
mitochondria.
Zygomycota
Not Monophyletic, but produce zygotes
Sexual and Asexual Reproduction
Glomeromycota
Asexual Plant Symbiotes
Glomeromycota
• Small group of
organisms
• Obligate symbiotes
with terrestrial
plants.
• No known evidence
for sexual
reproduction.
Basidiomycota
The Club (Basidium) Fungi
Basidiomycota
• Common fungi around us
• The basidium is the site of sexual division
• The basidiospores are produced by the
basidium
• Primary mycelium is monokaryotic
• Sexual mating results in the dikaryotic
secondary mycelium and basidiocarp.
Basidiomycota Life Cycle
Ascomycota
The Sac (Ascus) Fungi
Ascomycota
• About 75% of known fungi fall into this
group.
• Many are classified this way molecularly.
• Sexual reproduction is accomplished in
the ascus, found in ascocarps producing
ascospores
• Asexual reproduction produces conidia
• Some Ascomycota are yeast
Ascomycota Life Cycle
Ecology of Fungi
Symbiosis is Common
• Endophytes
• Lichens
• Mycorrhizae
Lichens
• Lichens are a
combination of fungi
and green algae
and/or
cyanobacteria.
• The fungi passes
through the cell wall
of the photosynthetic
partner.
Mycorrhizae
• Arbuscular Mycorrhizae – Glomeromycete
and terrestrial plants.
• Ectomycorrhizae – Basidiomycete and
trees.
Fungal Pathogens