Overview of Lecture: Fungi Read: Text ch 31 Bullet Points: • fungi – our sister group! • characteristics • fungusfocus.com • doctorfungus.com the biology of antifungal agents • new phylogeny (dang!!!) • microsporidia • chytrids • zygomycota • glomeromycota • basidiomycotaAlthough the fungal filaments and spores are microscopic, the colony can be very large with individuals of some species rivaling the mass of the largest animals or plants.In 2000, scientists discovered the mycelium of one giant individual of the fungus Armillaria ostoyae in Oregon that is 3.4 miles in diameter and spreads through 2,200 acres of forest. This fungus is at least 2,400 years old, qualifying it as one of Earth’s oldest and largest organisms.The similarity of fungal and mammalian cells creates a number of problems for designing drugs that are selectively toxic to fungal cells but not the human host. Antifungal agents currently ... attack one of four targets: Like mammalian cells, fungi are eukaryotes with DNA organized into chromosomes within the cell nucleus and distinct cytoplasmic organelles including endoplasmic reticulum, Golgi apparatus, mitochondria, and storage vacuoles. This homology to mammalian cells also extends to biosynthetic pathways ... {we’re all opisthokonts on this bus!} http://www.doctorfungus.org/thedrugs/antif_pharm.htmhttp://www.doctorfungus.org/thedrugs/antif_pharm.htmhttp://www.doctorfungus.org/thedrugs/antif_pharm.htm Azole antifungals can also inhibit many mammalian cytochrome P450-dependent enzymes involved in hormone synthesis or drug metabolism. Azole antifungals are particularly susceptible to drug interactions with medications metabolized through the P450 pathway. http://www.aber.ac.uk/biology/research/skellygrp/azole.htmhttp://www.doctorfungus.org/thedrugs/antif_pharm.htm There are three such agents at present, belonging to the chemical family known as the echinocandins: caspofungin, micafungin & anidulafungin. As would be predicted from their mechanism of action, these agents appear to be well-tolerated and have relatively fewer toxicities than polyene or azole-class antifungals. {fungal cytochrome P-450 3-A is similar to mammalian cytochrome P-450}http://www.doctorfungus.org/thedrugs/antif_pharm.htmFungal Defenses One of the major driving forces of evolution is the constant arms race between plants and animals and the microbial pathogens that infect them. The causes leaf mold on tomato plants. One of the ways tomato plants sense infections by C. fulvum is by detecting chitin, a component of fungal cell walls. {chitin is an indicator of fungal attack} In response, the fungus has evolved strategies to evade detection. { a fungal “cloaking device” } A preview of “innate immunity” (in tomatoes) and “cloaking” to avoid detection De Jonge et al. (Science, 2010; 329: 953-955) have now identified one such mechanism in C. fulvum, mediated by the effector protein Ecp6. Secreted Ecp6 is able to bind to chitin oligosaccharides that are released upon degradation of the fungal cell wall and sequester them so that they are not detected by tomato chitin receptors. {a similar “cloaking” strategy is used to protect rh+ fetuses from rh- moms} Proteins with domain structure similar to Ecp6 are conserved throughout the fungal kingdom, which suggests that chitin sequestration may represent a general mechanism used by fungi to evade immune detection.They are often used in the biological control of insect pests. The microsporidium, Thelohania solenopsae, causes the slow demise of a fire ant colony. ... the most common pathogens of fire ants in S. Am. A defining characteristic is the mechanism by which the spore contents are injected into the host's cytoplasm through a tube.A survey was conducted of 697 archived specimens of 3 species of Xenopus collected from 1879 to 1999 in southern Africa ... The earliest case of chytridiomycosis found was in a Xenopus laevis frog in 1938, Chytridiomycosis was a stable endemic infection in southern Africa for 23 years ... We propose that Africa is the origin of the amphibian chytrid and that the international trade in X. laevis that began in the mid-1930s was the means of dissemination.A common zygomycete is black bread mold: asexual reproMycorrhizal Root Dip Gel 13 different species of beneficial Endomycorrhizae & Ectomycorhizae. Increases Fruit/Vegetable yields. Promotes Fast Growth. News Feature Fungal roles in soil ecology: Underground networking John Whitfield Nature 449, 136-138 (13 September 2007)http://daphne.palomar.edu/wayne/ww0504.htm#soil The beautiful, red, fly agaric mushroom (Amanita muscaria) is unmistakable with its bright red cap covered with white scales. It contains the toxic alkaloid, muscimole; mycelial strands (lower) of Amanita muscaria on Pinus strobus http://www.pacificcoast.net/~mycolog/chapter17.htm seedlings of Douglas fir with and without ectomycorrhizal partners.http://www.perspective.com/nature/fungi/ascomycota.html Truffles & morels - ectomycorrhizal with tree roots ! half the 60k species live as lichen partners Penicillium (Penicillin)http://www.plant.uga.edu/labrat/ergot.htm LSD, an ergot derivative strongly interferes with the neurotransmitter serotonin. ... enhance another neurotransmitter, dopamine.http://www.perspective.com/nature/fungi/agaricus.html The Agaricus family includes the best known mushroom in the US: The white buttons sold generically as "mushrooms" are a cultivated variety of Agaricus The "wild" Crimini and Portabella mushrooms are also cultivars of this