''Neurospora'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Ascomycete Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The def ...

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

. The genus name, meaning "nerve spore" refers to the characteristic striations on the spores that resemble

axon An axon (from Greek ἄξων ''áxōn'', axis) or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, spelling differences) is a long, slender cellular extensions, projection of a nerve cell, or neuron, ...

s. The best known species in this genus is ''

Neurospora crassa ''Neurospora crassa'' is a type of red bread mold of the phylum Ascomycota. The genus name, meaning 'nerve spore' in Greek, refers to the characteristic striations on the spores. The first published account of this fungus was from an infestatio ...

'', a common

model organism A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Mo ...

biology Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and ...

. ''

Neurospora intermedia ''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 organi ...

'' var. ''oncomensis'' is believed to be the only mold belonging to ''Neurospora'' which is used in food production (to make

oncom Oncom ( IPA: ) is a fermented food which is one of the traditional staples of the Sundanese cuisine of Indonesia. There are two kinds of oncom: red oncom and black oncom. The food is closely related to tempeh; both are fermented using mold. U ...

Characteristics

''Neurospora'' species are

mold A mold () or mould () is one of the structures that certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal ...

s with broadly spreading

colonies A colony is a territory subject to a form of foreign rule, which rules the territory and its indigenous peoples separated from the foreign rulers, the colonizer, and their '' metropole'' (or "mother country"). This separated rule was often or ...

, with abundant production of

ascoma An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascoc ...

ta. Ascomata are superficial or immersed, perithecial and ostiolate or cleistothecial and non-ostiolate, hairy or glabrous, dark coloured.

Peridium The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of gasteroid fungi. Description Depending on the species, the peridium may vary from being paper-thin to thick and rubb ...

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.

Ascospore In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...

s 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 In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a fruiting body. *Anamorph: an asex ...

are known in only a relatively small number of species, which belong to the

fungi imperfecti The fungi imperfecti or imperfect fungi are fungi which do not fit into the commonly established taxonomic classifications of fungi that are based on biological species concepts or morphological characteristics of sexual structures because thei ...

genus ''Chrysonilia''. The type species of the genus is ''Neurospora sitophila'' Shear.

Systematics

The former genus ''

Gelasinospora ''Gelasinospora'' is a genus of fungi within the order Sordariales. Reproduction *''Gelasinospora'' as a genus is made up of perithecial fungi, meaning that they discharge their ascospores through an ostiole. *Spores do not germinate easily, n ...

'' is closely related and not resolved as a distinct monophyletic group, thus the former genus is nowadays included as a synonym of ''Neurospora''.

Species

*''

Neurospora africana ''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 organi ...

'' *''

Neurospora autosteira ''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 organi ...

'' *''

Neurospora bonaerensis ''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 organi ...

'' *''

Neurospora brevispora ''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 organi ...

'' *''

Neurospora caffra ''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 organi ...

'' *''

Neurospora calospora ''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 organi ...

'' *''

Neurospora cerealis ''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 organi ...

'' *''

Neurospora cratophora ''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 organi ...

'' *''

Neurospora dictyophora ''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 organi ...

'' *'' Neurospora discreta'' *'' Neurospora dodgei'' *'' Neurospora endodonta'' *'' Neurospora erythraea'' *'' Neurospora fallaciosa'' *''

Neurospora foveaconica ''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 organi ...

'' *'' Neurospora galapagosensis'' *'' Neurospora goundaensis'' *'' Neurospora hapsidophora'' *'' Neurospora heterospora'' *'' Neurospora himalayensis'' *'' Neurospora hippopotama'' *'' Neurospora hispaniola'' *'' Neurospora indica'' *''

'' *'' Neurospora inversa'' *'' Neurospora kobi'' *''

Neurospora lineolata ''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 organi ...

'' *'' Neurospora longispora'' *''

Neurospora macrospora ''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 organi ...

'' *'' Neurospora metzenbergii'' *'' Neurospora micropertusa'' *'' Neurospora mirabilis'' *'' Neurospora multiforis'' *'' Neurospora nigeriensis'' *'' Neurospora novoguineensis'' *'' Neurospora pannonica'' *'' Neurospora perkinsii'' *'' Neurospora pseudocalospora'' *'' Neurospora pseudoreticulata'' *''

Neurospora reticulata ''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 organi ...

'' *''

Neurospora retispora ''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 organi ...

'' *'' Neurospora saitoi'' *'' Neurospora santi-florii'' *'' Neurospora seminuda'' *'' Neurospora sitophila'' *'' Neurospora sphaerospora'' *'' Neurospora stellata'' *'' Neurospora sublineolata'' *'' Neurospora terricola'' *''

Neurospora tetrasperma ''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 organi ...

'' *'' Neurospora tetraspora'' *''

Neurospora toroi ''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 organi ...

'' *'' Neurospora udagawae'' *''

Neurospora uniporata ''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 organi ...

'' *'' Neurospora varians'' *'' Neurospora xylopiae''

As model organisms

''Neurospora'' is widely used in genetics as a

(especially ''N. crassa'') because it quickly reproduces, is easy to culture, and can survive on minimal media (inorganic

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

s, glucose, water and

biotin Biotin (also known as vitamin B7 or vitamin H) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. ...

agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from " ogonori" and " tengusa". As found in nature, agar is a mixture of two components, t ...

). The first studies of sexual reproduction in ''Neurospora'' were made by B. O. Dodge. ''Neurospora'' was later used by

George Wells Beadle George Wells Beadle (October 22, 1903 – June 9, 1989) was an American geneticist. In 1958 he shared one-half of the Nobel Prize in Physiology or Medicine with Edward Tatum for their discovery of the role of genes in regulating biochemical even ...

and

Edward Lawrie Tatum Edward Lawrie Tatum (December 14, 1909 – November 5, 1975) was an American geneticist. He shared half of the Nobel Prize in Physiology or Medicine in 1958 with George Beadle for showing that genes control individual steps in metabolism. The o ...

in X-ray mutation experiments to discover mutants that would differ in nutritional requirements. The results of their experiments led them to the

one gene-one enzyme hypothesis 1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sp ...

, in which they postulated that every

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

was encoded with its own

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. Research with ''Neurospora'' is reported semi-annually at the Neurospora Meeting at Asilomar, California, coordinated by the

Fungal Genetics Stock Center Established in 1960, the Fungal Genetics Stock Center is the main open repository for genetically characterized fungi. The FGSC is a member of the World Federation for Culture Collections and is a leading collection in thUS Culture Collection Netw ...

. 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 Bernard Ogilvie Dodge (18 April 1872 – 9 August 1960) was an American botanist and pioneer researcher on heredity in fungi. Dodge was the author of over 150 papers dealing with the life histories, cytology, morphology, pathology and genetics of ...

(1872–1960) *

George Beadle George Wells Beadle (October 22, 1903 – June 9, 1989) was an American geneticist. In 1958 he shared one-half of the Nobel Prize in Physiology or Medicine with Edward Tatum for their discovery of the role of genes in regulating biochemical eve ...

(

Nobel Prize in Physiology or Medicine The Nobel Prize in Physiology or Medicine () is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, acco ...

, 1958) *

Edward Tatum Edward Lawrie Tatum (December 14, 1909 – November 5, 1975) was an American geneticist. He shared half of the Nobel Prize in Physiology or Medicine in 1958 with George Beadle for showing that genes control individual steps in metabolism. The o ...

(

, 1958) *

Esther Lederberg Esther Miriam Zimmer Lederberg (December 18, 1922 – November 11, 2006) was an American microbiologist and a pioneer of bacterial genetics. She discovered the bacterial virus lambda phage and the bacterial fertility factor F, devised the f ...

Giles, N. H. Jr., Lederberg, E. Z., March 1948, "Induced reversions of biochemical mutants in Neurospora crassa", American Journal of Botany 35(3):150-157 * Norman Giles * David Perkins *

Robert Metzenberg Robert Lee Metzenberg (June 11, 1930 – July 15, 2007) was an American geneticist known for his work on genetic regulation and metabolism with Neurospora crassa. Education and early life Robert Lee Metzenberg was born in Chicago, Illinois, ...

Norman Horowitz Norman Harold Horowitz (March 19, 1915 – June 1, 2005) was an American geneticist at Caltech who achieved national fame as the scientist who devised experiments to determine whether life might exist on Mars. His experiments were carried out by ...

Herschel K. Mitchell Herschel Kenworthy Mitchell (November 27, 1913 – April 1, 2000) was an American professor of biochemistry who spent most of his career on the faculty at the California Institute of Technology. He was one of many researchers interested in vit ...

* Mary B. Mitchell *

Martha Merrow Martha Merrow (born 1957) is an American chronobiologist. She currently chairs the Institute of Medical Psychology at the Ludwig Maximilian University of Munich. Her career focuses primarily on investigating the molecular and genetic mechanisms o ...

Sexual reproduction

In the

heterothallic Heterothallic species have sexes that reside in different individuals. The term is applied particularly to distinguish heterothallic fungi, which require two compatible partners to produce sexual spores, from homothallic ones, which are capable ...

species ''Neurospora crassa'', the interaction of haploid strains of opposite

mating type Mating types are the microorganism equivalent to sexes in multicellular lifeforms and are thought to be the ancestor to distinct sexes. They also occur in multicellular organisms such as fungi. Definition Mating types are the microorganism equival ...

is necessary for the occurrence of sexual reproduction and the production of ascospores by

meiosis Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one c ...

. Ascospores then restore haploid individuals of either mating type. The life cycle phase is thus predominantly haploid, however, upon mating, the nuclei do not immediately fuse: karyogamy is delayed until the very onset of meiosis. The resulting mycelium is called a

heterokaryon In biology, a heterokaryon is a multinucleate cell that contains genetically different nuclei. This is a special type of syncytium. This can occur naturally, such as in the mycelium of fungi during sexual reproduction, or artificially as formed b ...

and is neither diploid nor haploid. The genus ''Neurospora'' also includes

homothallic In fungi and algae, homothallism refers to the condition in which a single individual or thallus carries the genetic determinants (i.e., both mating types or sexes) required to undergo sexual reproduction without the need for a distinct mating partn ...

species in which a single haploid individual carries both mating type loci and can undergo self-fertilization leading to meiosis and sexual reproduction. ''Neurospora africana'' is an example of such a species. Additionally, some "Neurospora" species are said pseudohomothallic. They carry both mating types, but in separate nuclei in the same individual. Two haploid nuclei originating from the same meiosis are packaged into one ascospore. The individual is thus permanently heterokaryotic. Examples of this mating system include "Neurospora tetrasperma" and "Neurospora tetraspora". Because heterothallic species necessarily undergo some degree of outcrossing they may benefit from a higher efficiency of selection because of higher effective recombination rates. In contrast, pseudohomothallic and homothallic species do not outcross (or rarely) and do not experience these benefits: in homothallics a reduced efficiency of negative selection has been shown. However, both hetero- and pseudohomothallic species benefit from the masking of deleterious recessive alleles in the heterokaryotic phase. In addition, all species derive the benefits of meiosis that include the removal of stress-induced

DNA damage DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. A weakened capacity for DNA repair is a risk factor for the development of cancer. DNA is constantly modified ...

s by

homologous recombination Homologous recombination is a type of genetic recombination in which genetic information is exchanged between two similar or identical molecules of double-stranded or single-stranded nucleic acids (usually DNA as in Cell (biology), cellular organi ...

al repair, and the formation of stress-resistant ascospores.

References

External links

*

Fungal Genetics Stock Center

Neurospora Meeting website
Neurospora strains
at the FGSC

at University of Edinburgh, UK. Website includes many movies and images of ''Neurospora''.

Fungal Genetics Reports

Montenegro-Montero A. (2010) "The Almighty Fungi: The Revolutionary Neurospora crassa". A historical view of the many contributions of this organism to molecular biology.

''Neurospora crassa'' genome {{Authority control Sordariales Sordariomycetes genera Taxa described in 1927