''Polytolypa'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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

containing the single species ''Polytolypa hystricis''. First classified in the

Onygenaceae The Onygenaceae are a family of fungi in the Ascomycota, class Eurotiomycetes. Genera These are the genera that are in the Onygenaceae, according to a 2021 review of fungal classification. Following the genus name is the taxonomic authority (t ...

family, as of 2008 it is considered to be in the Ajellomycetaceae, although there is still uncertainty as to its

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relationships with other similar genera. This species is only known from a single specimen derived in the laboratory from a specimen of dung of the

North American porcupine The North American porcupine (''Erethizon dorsatum''), also known as the Canadian porcupine, is a large quill-covered rodent in the New World porcupine family. It is the second largest rodent in North America, after the North American beaver ('' ...

, ''Erethizon dorsatum'', collected in Ontario, Canada. ''Polytolypa hystricis'' contains bioactive compounds that have antifungal activity.

Taxonomy, phylogeny, and naming

160px, left, ''Polytolypa hystricis'' was initially grown from the dung of the North American porcupine, ''Erethizon dorsatum'' (pictured).The genus was first described in 1993 by

University of Toronto The University of Toronto (UToronto or U of T) is a public university, public research university in Toronto, Ontario, Canada, located on the grounds that surround Queen's Park (Toronto), Queen's Park. It was founded by royal charter in 1827 ...

mycologists J.A. Scott and D.W. Malloch, who grew the fungus in moist chamber cultures of porcupine dung collected in Stoneleigh,

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...

, Canada. The

generic Generic or generics may refer to: In business * Generic term, a common name used for a range or class of similar things not protected by trademark * Generic brand, a brand for a product that does not have an associated brand or trademark, other ...

name ''Polytolypa'' is from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word ''poly'' (πολυ) meaning "many", and ''tolype'' (τολυπη), meaning "skein of yarn". The specific epithet ''hystricis'' comes from the Greek ''hystrix'' (υστριξ), or "porcupine". The genus has been classified in the

, a fungal

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

characterized by species capable of digesting human hair ''in vitro'', and with spores that are punctate (with minute surface punctures) when viewed with scanning electron microscopy. However, as Scott and colleagues demonstrated using traditional laboratory tests to determine keratinolytic activity, ''P. hystricus'' is not able to digest hair. There is still uncertainty as to its

relationships with other similar genera. ''Polytolypa'' is thought to be evolutionarily most closely related to the genera '' Malbranchea'' and '' Spiromastix''. The grouping of ''Polytolypa'' and ''Spiromastix'' represent a

sister clade In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to the Ajellomyces clade, based on analysis of partial nuclear LSU sequence data. However, the

s of ''Polytolypa'' are still unclear and await further study. The 10th edition of the ''Dictionary of the Fungi'' (2008) considers the genus to be in the Ajellomycetaceae family, although uncertainty with this classification is indicated in the entry; in contrast, the online mycological database

MycoBank MycoBank is an online database, documenting new mycological names and combinations, eventually combined with descriptions and illustrations. It is run by the Westerdijk Fungal Biodiversity Institute in Utrecht. Each novelty, after being screened ...

classifies the genus in the Onygenaceae.

Description

The ascus-containing reproductive structures, or ''

ascomata An ascocarp, or ascoma (), 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. Ascocarps are mos ...

'', are minute, spherical bodies, typically 200–400 μm in diameter. They start out white, but gradually become rusty brown in maturity. The ascomata, which may be clustered together in groups or scattered about, grow in a shallow layer of "hairs" (actually fungal

mycelia Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates ...

) called a

tomentum Tomentum may refer to: * Plant trichomes, a covering of closely matted or fine hairs on plant leaves. * Tomentum (anatomy), short, soft pubescence or a covering of fine, soft hairs. {{disambig ...

. The ascomata have "appendages" composed of numerous coiled, sometimes branched helices of hyphae that are coiled 3–15 times. The

ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or ...

s produced by ''Polytolypa'' are

ellipsoidal An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a surface that may be defined as the z ...

, yellow to yellow-orange in color, with dimensions of 2.5–5 by 3–4 μm. Viewed with a light microscope their surfaces appear to be smooth, but under scanning electron microscopy, they are revealed to be densely marked with punctures and small, hard, sharp projections. The structures that produce the ascospores are called asci. In ''Polytolypa'' they are numerous, spherical, and measure 9–10 by 12–13 μm. Each ascus contains eight ascospores, which are released when the ascus dissolves away at maturity. The anamorph (asexual form of the fungus) resembles the genus ''

Chrysosporium ''Chrysosporium'' is a genus of hyaline hyphomycetes fungi in the family Onygenaceae. ''Chrysosporium'' colonies are moderately fast-growing, flat, white to tan to beige in color; they often have a powdery or granular surface texture. Hyaline, ...

''.

Habitat and distribution

''Polytolypa hystricis'' is known only from the dung of the North American porcupine, ''Erethizon dorsatum''. Porcupine dens accumulate thick layers of nutrient-rich dung, hair and urine that are degraded by a succession of fungi. These fungi are disseminated by

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

s (such as insects) or by the porcupine themselves.

Bioactive compounds

Chemical analysis Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separati ...

has shown that ''Polytolypa hystricis'' contains a unique

triterpenoid Triterpenes are a class of chemical compounds composed of three terpene units with the molecular formula C30H48; they may also be thought of as consisting of six isoprene units. Animals, plants and fungi all produce triterpenes, including squal ...

chemical named polytolypin, as well two compounds known previously as metabolites from Scleroderris Canker ('' Gremmeniella abietina''). Both polytolypin and one of the previously identified compounds have "moderate" antifungal activity against the species '' Ascobolus furfuraceous'', while polytopin alone can inhibit the growth of ''

Candida albicans ''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is usu ...

''.

References

External links