Review from last time… Haploid? Diploid? Dikaryon? Nuclear state? Cellular state?

More definitions Teleomorph Anamorph Holomorph “Deuteromycetes”: a practical taxonomic strategy to deal with an alternative lifestyle Sexual (perfect) state Asexual (imperfect) state Asexual+sexual life cycle

Deuteromycetes – life without sex

What is a Deuteromycete? Formerly called Fungi Imperfecti Many common mold fungi do not have a known sexual life cycle Asexual state of a (typically) ascomycete fungus Also many zygomycetes and some basidiomycetes

Deuteromycetes – life without sex Advantages – speed (of reproduction, ~1 day) – flexibility (can maintain a well-adapted genome) –For experimenters and future evolution can maintain mutations in haploid nuclei (hyphae are multinucleate)

Deuteromycetes – life without sex Does this mean no genetic recombination? NO!... But recombination requires an inventive lifestyle...

Deuteromycetes – life without sex Does this mean no genetic recombination? NO!... But recombination requires an inventive lifestyle... Parasexuality mirrors the sexual cycle

Parasexual cycle part 1  heterokaryon formation Hyphal fusion is common Mutation is rare Heterokaryons are hyphae with two types of nuclei in any ratio

Heterokaryon sporulation Each nucleus can act independently in a heterokaryon

Karyogamy Fusion of nuclei is rare, 1 in 10 6 Creates a diploid nucleus Isolate by fast growth in minimal agar suspension Forced diploids are stable on minimal medium

Haploidization is common, 1 in 10 3 diploid nuclei

Horizontal genetic transfer Uptake of exogenous DNA Sources in nature  anastomoses between closely related eumycotan fungi Heteroplasmons and heterokaryons Exploited for cell, genetic and biotechnology research

Ecological relationships involving fungi

Ecological roles of fungi Saprobes Mycorrhizae Pathogens Parasites

Amphibious fungi Major role in recycling terrestrial inputs into aquatic systems Leaf fall ‘Conditioning’ plant material for animal consumption

Ingoldian spores are found in highly oxygenated water

Ingoldian spores are typical of highly oxygenated waters

Aeroaquatic fungi in still water Beverwykella

Helicoon

Competition between fungal individuals can produce barrage lines

Another fungus  insect connection

There’s no place like dung Major source of processed plant material Mastication, addition of lipids, vitamins, protein About 90% energy in herbivore dung is not utilized by the animal

Dung successions Recycle nutrients Basis of another food web  fungi to invertebrates Succession of fungal groups: zygomycete  ascomycete  basidiomycete –Nutrient assimilation? –Time to sporulation?  even spore distribution