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 the US Culture Collection Network Research Coordination Network .
The FGSC distributes strains of Neurospora and Aspergillus , as well as limited numbers of Fusarium , Magnaporthe and many strains from current fungal genome projects. [1]
In the 1980s and 1990s the FGSC added molecular materials including cloned genes, cloning vectors and gene libraries to the collection.
As more fungal genomes have been sequenced, the FGSC has re-evaluated the definition of a genetic system. This has led them to expand the collection, with additional materials including strains from genome programs [2] and mutant collections for organisms such as Neurospora crassa , Aspergillus nidulans , Cryptococcus neoformans , and Candida albicans .
As a genetic repository, the FGSC has always endeavored to represent the diversity of genetic materials available. To that end, they hold large numbers of strains of a few different species. More specifically, strains from 76 different species representing 23 different genera. Of these, there are more than ten strains for only nineteen different species. These strains have been deposited by 310 different individuals, 64 of whom have deposited only one strain. The FGSC also holds a number of non-accessioned strains including the wild-type strain collection of Dr. David Perkins as well as Neurospora strains from a number of other researchers who have retired. These are held with the understanding that they will keep them as long as space is available. They are not curated and are available on an as-is basis. Other strain collections include Allomyces (pdf), Aspergillus niger, Ustilago madis, and Neurospora strains from the historical Tatum lab collection
In the period from January 1998 to December 2018, the FGSC distributed over 630,000 cultures including nearly 5,000 individual mutants and over 20,000 gene deletion mutants arrayed in 96-well format. Since the development of the FGSC database in 1987, the FGSC has sent out over 650,000 strains.
The FGSC was founded in 1960 at Dartmouth College with a grant from the US National Science Foundation. Dr. R. Barratt was the first Director of the FGSC. The FGSC has moved three times since then and has been housed at Humboldt State University, the University of Kansas Medical Center the University of Missouri–Kansas City, and since 2014, Kansas State University . At KU Med Center Dr. J. Kinsey was director and he worked on genetics of amino acid metabolism and later identified the transposon "Tad" in a Neurospora crassa strain from Adiopodoume, Ivory Coast. [3] At UMKC, Dr. Michael Plamann who worked on cytoskeleton dynamics was the director. [4] Since 2014, Dr. John Leslie of the Kansas State University Department of Plant Pathology has been Director.
The FGSC has had three curators since it was established. William (Bill) Ogata was the first curator, serving until he retired in 1981. He was succeeded by Craig Wilson at Humboldt. Mr. Wilson moved with the collection to Kansas City where in 1995 Dr. Kevin McCluskey became the curator. Since 1995 the FGSC holdings grew from 8,000 strains to well over 25,000 strains. [5] Similarly, best practice guides for culture collections became available and were integrated into the FGSC practices. [6]
For many years the FGSC was supported by the US National Science Foundation under their Living Stock Collection program. [7] Beginning in 2015, the FGSC has been supported by the Kansas State University College of Agriculture and by fees paid by clients.
One of the main goals of the FGSC is to make research with filamentous fungi (mold) more accessible. To that end the FGSC web-site hosts extensive protocols [8] for Neurospora and Aspergillus. Other materials and services are available on a case-by-case basis.
Most research activities at the FGSC are aimed at adding value to the materials in the collection. Specific projects have included strain improvement, identification of unknown markers and production of multiply marked strains. Recent work includes the characterization of otherwise anonymous temperature sensitive mutations in Neurospora and characterization of otherwise anonymous classical mutants in collaboration with the US Department of Energy JGI.
The FGSC was a part of the Neurospora Functional Genomics program. [9] and accessioned over 13,000 gene deletion mutants together comprising a whole genome deletion set between 2006 and 2014.
A point mutation is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a DNA or RNA sequence of an organism's genome. Point mutations have a variety of effects on the downstream protein product—consequences that are moderately predictable based upon the specifics of the mutation. These consequences can range from no effect to deleterious effects, with regard to protein production, composition, and function.
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 infestation of French bakeries in 1843.
Aspergillus fumigatus is a species of fungus in the genus Aspergillus, and is one of the most common Aspergillus species to cause disease in individuals with an immunodeficiency.
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 of sexual reproduction from a single organism.
Aspergillus is a genus consisting of several hundred mold species found in various climates worldwide.
Complementation refers to a genetic process when two strains of an organism with different homozygous recessive mutations that produce the same mutant phenotype have offspring that express the wild-type phenotype when mated or crossed. Complementation will ordinarily occur if the mutations are in different genes. Complementation may also occur if the two mutations are at different sites within the same gene, but this effect is usually weaker than that of intergenic complementation. When the mutations are in different genes, each strain's genome supplies the wild-type allele to "complement" the mutated allele of the other strain's genome. Since the mutations are recessive, the offspring will display the wild-type phenotype. A complementation test can test whether the mutations in two strains are in different genes. Complementation is usually weaker or absent if the mutations are in the same gene. The convenience and essence of this test is that the mutations that produce a phenotype can be assigned to different genes without the exact knowledge of what the gene product is doing on a molecular level. American geneticist Edward B. Lewis developed the complementation test.
Neurospora is a genus of Ascomycete fungi. The genus name, meaning "nerve spore" refers to the characteristic striations on the spores that resemble axons.
Aspergillus nidulans is one of many species of filamentous fungi in the phylum Ascomycota. It has been an important research organism for studying eukaryotic cell biology for over 50 years, being used to study a wide range of subjects including recombination, DNA repair, mutation, cell cycle control, tubulin, chromatin, nucleokinesis, pathogenesis, metabolism, and experimental evolution. It is one of the few species in its genus able to form sexual spores through meiosis, allowing crossing of strains in the laboratory. A. nidulans is a homothallic fungus, meaning it is able to self-fertilize and form fruiting bodies in the absence of a mating partner. It has septate hyphae with a woolly colony texture and white mycelia. The green colour of wild-type colonies is due to pigmentation of the spores, while mutations in the pigmentation pathway can produce other spore colours.
Fungi are a diverse group of organisms that employ a huge variety of reproductive strategies, ranging from fully asexual to almost exclusively sexual species. Most species can reproduce both sexually and asexually, alternating between haploid and diploid forms. This contrasts with most multicellular eukaryotes such as mammals, where the adults are usually diploid and produce haploid gametes which combine to form the next generation. In fungi, both haploid and diploid forms can reproduce – haploid individuals can undergo asexual reproduction while diploid forms can produce gametes that combine to give rise to the next generation.
Extranuclear inheritance or cytoplasmic inheritance is the transmission of genes that occur outside the nucleus. It is found in most eukaryotes and is commonly known to occur in cytoplasmic organelles such as mitochondria and chloroplasts or from cellular parasites like viruses or bacteria.
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.
David Dexter Perkins was an American geneticist, a member of the faculty of the Department of Biology at Stanford University for more than 58 years, from 1948 until his death in 2007. He received his PhD in Zoology in 1949 from Columbia University. A member of the National Academy of Sciences, he served as president of the Genetics Society of America in 1977. In a scientific career that spanned more than six decades, Perkins collaborated on more than 300 papers. His associates included many graduate students and postdoctoral fellows who went on to scientific careers throughout the world.
Robert Lee Metzenberg was an American geneticist known for his work on genetic regulation and metabolism with Neurospora crassa.
The one gene–one enzyme hypothesis is the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway. The concept was proposed by George Beadle and Edward Tatum in an influential 1941 paper on genetic mutations in the mold Neurospora crassa, and subsequently was dubbed the "one gene–one enzyme hypothesis" by their collaborator Norman Horowitz. In 2004, Horowitz reminisced that "these experiments founded the science of what Beadle and Tatum called 'biochemical genetics.' In actuality they proved to be the opening gun in what became molecular genetics and all the developments that have followed from that." The development of the one gene–one enzyme hypothesis is often considered the first significant result in what came to be called molecular biology. Although it has been extremely influential, the hypothesis was recognized soon after its proposal to be an oversimplification. Even the subsequent reformulation of the "one gene–one polypeptide" hypothesis is now considered too simple to describe the relationship between genes and proteins.
Uniparental inheritance is a non-Mendelian form of inheritance that consists of the transmission of genotypes from one parental type to all progeny. That is, all the genes in offspring will originate from only the mother or only the father. This phenomenon is most commonly observed in eukaryotic organelles such as mitochondria and chloroplasts. This is because such organelles contain their own DNA and are capable of independent mitotic replication that does not endure crossing over with the DNA from another parental type. Although uniparental inheritance is the most common form of inheritance in organelles, there is increased evidence of diversity. Some studies found doubly uniparental inheritance (DUI) and biparental transmission to exist in cells. Evidence suggests that even when there is biparental inheritance, crossing-over doesn't always occur. Furthermore, there is evidence that the form of organelle inheritance varied frequently over time. Uniparental inheritance can be divided into multiple subtypes based on the pathway of inheritance.
Podospora anserina is a filamentous ascomycete fungus from the order Sordariales. It is considered a model organism for the study of molecular biology of senescence (aging), prions, sexual reproduction, and meiotic drive. It has an obligate sexual and pseudohomothallic life cycle. It is a non-pathogenic coprophilous fungus that colonizes the dung of herbivorous animals such as horses, rabbits, cows and sheep.
The frequency (frq) gene encodes the protein frequency (FRQ) that functions in the Neurospora crassa circadian clock. The FRQ protein plays a key role in circadian oscillator, serving to nucleate the negative element complex in the auto regulatory transcription-translation negative feedback-loop (TTFL) that is responsible for circadian rhythms in N. crassa. Similar rhythms are found in mammals, Drosophila and cyanobacteria. Recently, FRQ homologs have been identified in several other species of fungi. Expression of frq is controlled by the two transcription factors white collar-1 (WC-1) and white collar-2 (WC-2) that act together as the White Collar Complex (WCC) and serve as the positive element in the TTFL. Expression of frq can also be induced through light exposure in a WCC dependent manner. Forward genetics has generated many alleles of frq resulting in strains whose circadian clocks vary in period length.
The white collar--2 (wc-2) gene in Neurospora crassa encodes the protein White Collar-2 (WC-2). WC-2 is a GATA transcription factor necessary for blue light photoreception and for regulating circadian rhythms in Neurospora. In both contexts, WC-2 binds to its non-redundant counterpart White Collar-1 (WC-1) through PAS domains to form the White Collar Complex (WCC), an active transcription factor.
Jay Dunlap is an American chronobiologist and photobiologist who has made significant contributions to the field of chronobiology by investigating the underlying mechanisms of circadian systems in Neurospora, a fungus commonly used as a model organism in biology, and in mice and mammalian cell culture models. Major contributions by Jay Dunlap include his work investigating the role of frq and wc clock genes in circadian rhythmicity, and his leadership in coordinating the whole genome knockout collection for Neurospora. He is currently the Nathan Smith Professor of Molecular and Systems Biology at the Geisel School of Medicine at Dartmouth. He and his colleague Jennifer Loros have mentored numerous students and postdoctoral fellows, many of whom presently hold positions at various academic institutions.