Terminology of mycology

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Hello,

Here you will find some definitions – basic terms as they relate to mycology.

A.    Basic Structures

1.    Hypha (hyphae plural) –  fundamental tube-like structural units of fungi.

a.    Septate – divided by cross walls

b.    Aseptate – lacking cross walls

a.    Aerial – growing or existing in the air2.    Mycelium – a mass / mat of hyphae forming the vegative portion of the fungus

b.    Vegetative – absorbs nutrients

c.    Fertile  – bears conidia or spores for reproduction

B.    Spores

Sporulation & Spores – preferred terms used when there is a merging of nuclear material / genes combine.  Fusion of nuclear material.

Self-fertile = homothallic.  Mating types = heterothallic.

Sexual spores  – fusion of nuclei

1.    Ascospore – spore formed in a sac-like cell known as an ascus, the shape of which aids in identification of the fungus.  Often eight (8) spores formed. (sexual).  (Ascomycetes)

2.    Basidiospore – sexual spore (union of two nuclei) produced on a specialized club-shaped structure, called a basidium.  (Basidiomycetes)

3.    Zygospore – a thick-walled spore formed during sexual reproduction in the Phycomycetes

Asexual  spores – most common type

4.    Conidia – asexual fungal spores borne externally in various ways from a conidiophore; often referred to a macro- and microconidia.  (Ascomycetes & Deuteromycetes). Macroconidia are multicellular
Microconidia are unicellular

5.    Arthroconidium (Arthrospore) – special type of asexual spore formed by disarticulation of the mycelium.

6.    Blastoconidia / Blastospore –  asexual spore formed from a budding process along the mycelium or from another blastospore.  (class Ascomycetes)

7.    Chlamydospore – thick-walled resistant  asexual spore formed by direct differentiation of the mycelium (concentration of protoplasm and nutrients)

8.    Sporangiospore – an asexual spore contained in a sporangium at the end of a sporangoiphore of the taxonomic class Phycomycetes

9.    Thallospore – asexual spore produced on a thallus (hypha).  (Deuteromycetes)

Miscellanous terms

1.    Ascus – sac-like structure containing (usually eight) ascospores developed during sexual reproduction in the Ascomycetes.

2.    Asexual reproduction – spores (reproductive bodies of a fungus) are formed directly from the vegetative mycelium or from specialized hyphae.

3.    Chromoblastomycosis – a subcutaneous mycosis often the result of traumatic inoculation of a dematiaceous fungus into the skin; etiologic agents include species of Cladosporium, *Fonsecaea, Exophiala, & Phialophora

4.    Coenocytic – a cell or an aseptate hypha containing numerous nuclei.

 

5.    Conidiophore – a specialized branch of hypha on which conidia are developed.

6.    Dematiaceous – pigmented, dark in color, usually gray to black.

8.    Diphasic (dimorphic) – the ability of some fungi to grow as either yeast or filamentous stages, depending on conditions of growth.7.    Dermatophyte – fungi that cause superficial mycoses.

9.    Ectothrixic – ability of the fungus to grow on the outside of a hair shaft.

10.    Endothrixic – ability of the fungus to grow and penetrate into the hair shaft.

11.    Endogenous – derived from internal source.

12.    Exogenous – derived from external source.

13.    Eukaryotes – organisms possessing a true nucleus (such as fungi) as opposed to prokaryotes which do not contain a nuclear membrane (such as bacteria).

14.    Fungemia – fungal blood infection

15.    Fungi Imperfecti – a large class of fungi with septate hyphae in which the asexual state of reproduction is known, but not the sexual state.  They are also called Deuteromycetes and include the majority of medically significant fungi.

16.    Germ Tube – small projections which arise from cells of certain yeasts; indicates the onset of hyphal formation.

17.    Hyaline – colorless, clear.

18.    Mold – term generally referring to filamentous fungi

19.    Mycetoma – a clinical syndrome of localized, tumorous lesions in cutaneous and subcutaneous tissues due to infections, often a foot,  with actinomycetes or fungi.

20.    Mycosis – a disease caused by a fungus

21.    Mycotoxins – toxins of fungal origin

22.    Oospore –  also called zygospore, a sexual spore produced through the fusion of two unlike nuclei (class Phycomycetes)

24.    Phycomycetes – a class of fungi forming a coenocytic mycelium with stiff sporangiophores that bear sporangiospores contained in a sporangium23.    Perfect fungi – fungi having sexual and asexual reproductive stages

25.    Pseudohyphae – a chain of elongated budding cells that have failed to detach (not true hyphae)

26.    Ringworm  – term used to describe circular or ring-like skin lesions produced by dermatophytes

Ringworm

27.    Rhizoids – root-like structures

28.    Saprobe (Saprophyte) – any plant organism that obtains its nourishment from dead organic matter

29.    Sexual reproduction – zygote / spore formation follows the fusion of two haploid nuclei

30.    Sporangiophore – a special aerial hypha or stalk bearing a sporangium

31.    Sporangium – a sac or cell containing spores produced asexually

32.    Spore – generally the reproductive body of a fungus; occasionally, a resistant body for adverse environment

33.    Sterigmata – a specialized structure that arises from a basidium and supports basidiospores

34.    Sporotrichosis – mycosis the result of inoculation with Sporothrix schenckii, lymphocutaneous type is most common

35.    Telemorph – the sexual form of a fungus

36.    Thallospore – spore formed by a change in portions of the thallus

37.    Thallus – the vegetative body of a fungus

38.    Tinea  (Ringworm) – Prefix used with the infected area of the body to indicate a cutaneous mycosis

39.    Yeast – pasty or mucoid form of fungus growth, microscopically shows a predominance of budding cells

40.    Zoophilic – dermatophytes which are parasitic on lower animals as well as man

More about fungi can be found HERE

Big thanks to www.austincc.edu/ddingley/MLAB1331/LectureGuide/Mycology.doc.