L6 The Phylum formerly known as the Zygomycota Flashcards
What is the current classification status of Zygomycota?
Zygomycota is now classified as incertae sedis, indicating uncertain placement. It includes at least four polyphyletic clades: Mucoromycotina, Entomophthoromycotina, Kickxellomycotina, and Zoopagomycotina, all supported as monophyletic by nuclear SSU rDNA sequences.
What recent research has contributed to the reclassification of Zygomycota?
Spatafora et al. (2016) sampled 46 fungal genomes and aligned 192 conserved orthologous proteins, including 25 Zygomycete taxa, proposing a new classification scheme based on protein sequence data, although it remains disputed.
What are the general features of Mucoromycotina?
Mucoromycotina includes saprophytes and parasites with rapid growth, abundant asexual spore production, and the ability to reproduce sexually with persistent structures like zygospores
Describe the sexual reproduction process in Mucoromycotina.
Sexual reproduction involves compatible haploid mycelia fusing to form a zygosporangium. Plasmogamy occurs first, followed by karyogamy, leading to a thick-walled zygospore that can withstand harsh conditions.
What is the life cycle of Rhizopus stolonifer?
Rhizopus stolonifer has both asexual and sexual phases, with asexual reproduction occurring through sporangiospores and sexual reproduction through the formation of zygosporangia from compatible mating types.
Explain the unique dispersal mechanism of Pilobolus
Pilobolus uses phototropism to aim its sporangium towards light, building turgor pressure to launch spores up to 2 meters, which adhere to nearby vegetation to be consumed by herbivores.
What is the ecological role of Entomophthoromycotina?
This subphylum consists of insect pathogens that infect and kill various insect hosts, such as flies and caterpillars, often used as biological control agents.
Describe the infection process of Entomophthora muscae.
Entomophthora muscae infects house flies by forcing sporangiospores through the exoskeleton, leading to sporangium formation outside the body for spore dispersal.
What are the key features of Kickxellomycotina?
Kickxellomycotina features regularly septate hyphae, forms complex asexual spores, and is primarily saprobic, often found in soil or dung.
Provide an example of a species from Kickxellomycotina and its characteristics.
Coemansia species grow in soil or dung, forming tall sporangiophores with side branches that produce asexual spores released in sticky droplets, enhancing dispersal.
What are the general characteristics of Zoopagomycotina?
Zoopagomycotina are mostly obligate parasites or pathogens of other organisms, including insects and microscopic soil animals, characterized by simple sporangiophore morphology.
Describe Smittium sp. and its ecological relationship.
Smittium sp. is an obligate endoparasite of aquatic insect larvae, colonizing the gut region and sometimes having a mutualistic relationship that enhances larval survival.
What defines the Phylum Glomeromycota?
lomeromycota are exclusively soil fungi forming mutualistic relationships with plants (mycorrhizae), are obligate symbionts, and reproduce asexually through large, thick-walled spores.
How are Glomeromycota studied in research?
They can be studied using pot cultures with whole plants or transformed root organ cultures that allow for sterile co-cultures and non-destructive monitoring of fungal growth.
What unique structures are associated with Glomeromycota?
Key structures include vesicles, arbuscules, and asexual spores, all of which are critical for their symbiotic relationships with plant roots.
