BIOEE 1780 Evolutionary Biology & Diversity - Biodiversity 4 (Fungi)

Major Clades of Opisthokonts (2)

1) Fungi

2) Choanoflagellates + Animalia (Synapomorphy is presence of cadherins - proteins that help with cell-cell adhesion)

Synapomorphy for Opisthokonts

single posterior flagellum (often either manifests sperm cells or as been lost [most Fungi] )

Synapomorphies for Fungi (2)

1) Chitin (Polysaccharide) in Cell Wall (strengthens walls of hyphae)

2) Absorptive Heterotrophy - absorbs nutrients from environment via secrete enzyme with digest organic materials from environment

Major Groups of Fungi (4)

1) Microsporidia (Sister to Chytrids)

2) Chytrids (Sister to Arbuscular Mychorrhizae + Dikarya Clade)

3) Arbuscular Mycorrhiza (sister to Dikarya)

4) Dikarya

Microsporidia (2 Synapomorphies)

intracellular obligate parasites due to reduced mitochondria (1), infecting hosts with a polar tube (2) that releases spores into host; acts as a dangerous human pathogen

Chytrids (1 Synapomorphy + Ecological Impact)

fungi species that have retained flagella on gametes, thus being mostly aquatic; Amphibian Killer Fungus

Arbuscular Mycorrhizae

fungi that have microscopic fungal hyphae extend into the root of a plant; has mutualism with plant, increasing surface area of absorption to allow certain plants to live in distinct environments while obtaining photosynthates from plant

Structure of Fungi (3)

1) Hyphae - filaments that made up body of fungi; site of nutrient absorption

2) Mycelium - network of hyphae that form body

3) Septa (only in Dikarya) - cross walls that separate hyphae into cells

Synapomorphies of Dikarya (2)

1) Dikaryon Stage of Life cycle - two nuclei coexist within each cell

2) Septate Hyphae - hyphae are separated by septa (cross walls)

Major Groups of Dikarya (2)

1) Ascomycota (sac/cup fungi) - spores burst out of ascus under pressure

2) Basidiomycota (club fungi) - produces spores on basidium (prototypical mushroom top), from which spores fall

Examples of Ascomycota (5)

1) Yeast - unicellular with asexual reproduction

2) Truffles

3) Morels

4) (Most) Lichen

5) (Most) Molds

What type of fungi is a model organism?

Baker's/Brewer's Yeast [Diakarya -> Ascomycota]:

Saccharomyces cerevisiae

Mating Types

analogous of "sex" for fungi; set of two groups, where fungi of same mating type can't sexually reproduce with one another

Fungal Lifestyles (4)

1) Saprobic - decomposers: take up nutrients from dead organic matter

2) Predators - secretes sticky substances to trap organisms & grow within them

3) Parasitic

4) Mutualism (Ex: Lichens & Arbuscular Mycorrhizae)

Examples of Basidiomycota (4)

1) Mushroom

2) Rusts - plant pathogen

3) Smuts - plant pathogen

4) Brackets