What is a hypha in fungi?
A hypha is a long, branching, filamentous structure produced by fungi, oomycetes, and actinobacteria. In most fungi, hyphae are the main mode of vegetative growth. Collectively, a mass of hyphae is called a mycelium.
Questions about Hypha
Short answers, pulled from the story.
What is the Spitzenkörper and what role does it play in hyphal growth?
The Spitzenkörper is an intracellular organelle located at the tip of a growing hypha, composed of membrane-bound vesicles carrying cell wall components. It receives vesicles from the Golgi apparatus and releases them toward the cell membrane, where they build new wall and membrane material through exocytosis. The rate of hyphal tip growth is directly regulated by the rate at which the Spitzenkörper moves along the apex.
What are septa in fungal hyphae?
Septa are internal cross-walls that divide most fungal hyphae into individual cells. They are typically perforated by pores large enough for ribosomes, mitochondria, and sometimes nuclei to flow between neighboring cells. Fungi lacking septa are described as aseptate or coenocytic.
What is the difference between monomitic, dimitic, and trimitic fungi?
The terms refer to how many types of hyphae a fungal fruiting body contains. Monomitic fungi, such as fleshy agaric mushrooms, contain only generative hyphae. Dimitic fungi contain generative hyphae plus either skeletal or binding hyphae. Trimitic fungi, such as Trametes, contain all three types. E. J. H. Corner introduced these terms in 1932 to improve the classification of polypores.
What are haustoria and arbuscules in fungal hyphae?
Haustoria are modified hyphae formed by parasitic fungi that penetrate host cells to absorb nutrients. Arbuscules are branched hyphal structures formed by mutualistic mycorrhizal fungi inside plant root cells, facilitating nutrient and water exchange between the fungus and plant.
What are pseudohyphae and how do they differ from true hyphae?
Pseudohyphae are filamentous chains formed by yeasts when cells elongate but remain attached after budding rather than separating completely. They differ from true hyphae by their mode of growth, relative fragility, and the absence of cytoplasmic connections between cells. Some yeasts can also form true septate hyphae.