Neurospora

Neurospora is a genus of Ascomycete fungi. The genus name, meaning "nerve spore" refers to the characteristic striations on the spores that resemble axons.

The best known species in this genus is Neurospora crassa, a common model organism in biology. Neurospora sitophila (or also N. intermedia) is believed to be the only mold(s) belonging to Neurospora used in food production (oncom)^[1].

Characteristics

Neurospora species are molds with broadly spreading colonies, with abundant production of ascomata. Ascomata are superficial or immersed, perithecial and ostiolate or cleistothecial and non-ostiolate, hairy or glabrous, dark coloured. Peridium membranaceous, asci cylindrical, clavate or subspherical, with a persistent or evanescent wall, usually with a thickened and non-amyloid annular structure at the apex, usually 8-spored. Ascospores broadly fusiform, ellipsoidal, or nearly spherical, unicellular, hyaline to yellowish brown or olive-brown, becoming dark and opaque at maturity, ascospore wall with longitudinal ribs or pitted, occasionally nearly smooth, 1–2 (but rarely up to 12) germ pores disposed at the ends of the ascospores, gelatinous sheaths or appendages are absent. Anamorphs are known in only a relatively small number of species, which belong to the fungi imperfecti genus Chrysonilia. The type species of the genus is Neurospora sitophila Shear^[2]

Systematics

The former genera Gelasinospora and Neurospora are closely related and not resolved as monophyletic groups^[3], thus the former genus is nowadays included in Neurospora^[4]. The genus includes the following species:

• N. africana
• N. bonaerensis
• N. brevispora
• N. caffera
• N. calospora
• N. cerealis
• N. crassa
• N. cratophora
• N. dictyophora
• N. discreta
• N. dodgei
• N. himalayensis
• N. hippopotama
• N. indica
• N. intermedia
• N. inversa
• N. kobi
• N. lineolata
• N. longispora
• N. novoguineensis
• N. pannonica
• N. pseudocalospora
• N. pseudoreticulata
• N. reticulata
• N. sitophila
• N. tetrasperma

Neurospora as model organisms

Neurospora is notable because it was used by George Wells Beadle and Edward Lawrie Tatum in X-ray mutation experiments in order to discover mutants that would differ in nutritional requirements. The results of their experiments led them to the one gene-one enzyme hypothesis, in which they postulated that every enzyme was encoded with its own gene.

Nowadays they are widely used model organisms in genetics, especially N. crassa. It was chosen because it is quickly reproducing, is easy to culture, and was already able to survive on minimal media (inorganic salts, glucose, water and biotin in agar).

Research with Neurospora is reported semi-annually at the Neurospora Meeting at Asilomar, coordinated by the Fungal Genetics Stock Center. Mutant and wild-type strains of Neurospora are available from the FGSC. The FGSC also publishes the Fungal Genetics Reports.

Important people in Neurospora research:

• Bernard Ogilvie Dodge (1872-1960)
• George Beadle (Nobel Prize in Physiology or Medicine, 1958)
• Edward Tatum (Nobel Prize in Physiology or Medicine, 1958)
• David Perkins
• Robert Metzenberg

References

External links

• [1] Fungal Genetics Stock Center
• [2] Neurospora Meeting website
• Neurospora strains at the FGSC
• Neurospora genome projects
• Fungal Cell Biology Group at University of Edinburgh, UK. Website includes many movies and images of Neurospora.
• [3] Fungal Genetics Reports