L5Microsporidia, Blastocladiomycota, and Neocallimastigomycota, Flashcards
What is the primary ecological role of Microsporidia?
Microsporidia are unicellular obligate endoparasites that primarily infect invertebrates and vertebrates, playing significant roles in host population dynamics.
How many genera and species of Microsporidia are described?
Approximately 200 genera and 1,400 species of Microsporidia are described.
What distinguishes Microsporidia from other fungi?
Microsporidia lack mitochondria, possess mitosomes, and have a highly reduced ribosomal RNA and small genomes (2.3 to 19.5 Mb).
What is the life cycle of Microsporidia?
The life cycle includes an intracellular and extracellular spore stage, with infection initiated by the ejection of the polar filament into the host cell.
Which Microsporidia species are significant human pathogens?
Species such as Enterocytozoon bieneusi and Encephalitozoon cuniculi are notable human pathogens.
What symptoms are associated with human microsporidiosis?
Symptoms can include chronic diarrhea, abdominal pain, and wasting, particularly in immunocompromised individuals.
What is the ecological niche of Blastocladiomycota?
They thrive in aquatic environments and moist soils, serving as saprobes, parasites, or pathogens of plants and invertebrates.
How does sexual reproduction occur in Blastocladiomycota?
Sexual reproduction involves the fusion of gametes to form a diploid thallus, which later undergoes meiosis to produce haploid zoospores.
What is a model species of Blastocladiomycota?
Allomyces arbusculus is a key model species used for molecular and biochemical studies.
Describe the unique life cycle of Allomyces arbusculus.
Allomyces arbusculus undergoes an alternation of generations, with both haploid and diploid stages, and features anisogamous gametes attracted by pheromones.
What is the primary habitat of Neocallimastigomycota?
They are obligate anaerobes found in the rumen or hindgut of herbivorous mammals, where they aid in the digestion of plant materials.
How do Neocallimastigomycota contribute to their hosts’ digestion?
They decompose cellulose and hemicellulose, providing essential nutrients to the host by breaking down complex carbohydrates.
What are hydrogenosomes, and why are they important for Neocallimastigomycota?
Hydrogenosomes are organelles that enable anaerobic energy production, producing H2 and other fermentation end products crucial for metabolic processes.
What is the significance of Neocallimastigomycota in biotechnology?
They have potential applications in probiotics for livestock health, production of polysaccharide-degrading enzymes, and biofuel production.
Describe the life cycle of Neocallimastigomycota.
They reproduce asexually through the production of flagellated zoospores, which are released in response to food ingestion by the host.
What are the main characteristics of Microsporidia?
Microsporidia are unicellular, obligate endoparasites, typically measuring 1 to 40 µm, with a cell wall containing chitin. They lack traditional mitochondria, instead possessing mitosomes, and have highly reduced genomes.
Discuss the unique reproduction of Neocallimastigomycota.
They primarily reproduce asexually via flagellated zoospores, which are released in response to substrate availability, with no sexual reproductive stages identified to date.
How are Neocallimastigomycota utilized in biotechnology?
They are explored for use as probiotics in livestock, as sources of polysaccharide-degrading enzymes for industrial applications, and for biofuel production by converting lignocellulosic biomass into fermentable sugars.
Describe the metabolic adaptations of Neocallimastigomycota.
They utilize hydrogenosomes for anaerobic respiration, producing hydrogen and organic acids as byproducts of fermentation, which are critical for their energy metabolism.
Explain the role of Neocallimastigomycota in herbivore digestion.
They aid in the digestion of cellulose and hemicellulose in the rumen, producing cellulases and other enzymes to break down complex plant materials into simpler compounds.
What are the characteristics of the sexual reproduction process in Blastocladiomycota?
Sexual reproduction involves anisogamous gametes, with male gametes attracted to female gametes by pheromones, resulting in zygote formation and subsequent diploid thallus development.
