Micoletzkya | |
---|---|
Scientific classification | |
Kingdom: | |
Phylum: | |
Class: | |
Order: | |
Family: | |
Genus: | Micoletzkya Weingärtner 1955 |
Micoletzkya is a genus of predatory bark-beetle-associated nematodes in the family Diplogastridae. [1] [2] The genus was named for the Austrian nematologist Heinrich Micoletzky. As of 2013 it consists of 25 described species. [3]
Nematodes of Micoletzkya live in symbiosis with bark beetles. [4] The hosts include economically important species across North America and Europe such as the mountain pine beetle Dendroctonus ponderosae and European spruce bark beetle Ips typographus. [4] [5] [6] The life history of the nematodes is closely linked to that of their hosts. Infective (dauer) larvae of Micoletzkya attach themselves onto the body surface of a beetle for transmission and resume their development in host breeding galleries. In the bark beetle galleries, nematodes go through a few free-living generations, presumably feeding on beetle-associated microorganisms and other nematodes, after which dauer larvae develop and attach to newly emerging bark beetles for transmission. [4]
Micoletzkya nematodes are remarkably host specific, with most species found in association with only a single host species. Nematodes of this genus are vertically transmitted within host populations, which fosters cospeciation with bark beetles and adaptation to particular groups of hosts. Phylogenetic evidence suggests that diversification of the genus was largely influenced by the evolutionary radiation of bark beetles. [6]
Like many other members of the diplogastrid family, [7] Micoletzkya nematodes have movable opposing teeth and show a mouth dimorphism. Dimorphic species of the genus can express two alternative mouth phenotypes: stenostomatous (narrow mouth and small teeth) and eurystomatous (wide mouth and large teeth). [8] The two alternative phenotypes are thought to represent a resource polyphenism, or specialized for feeding on different foods, such as microorganisms and other nematodes respectively. [9]
Micoletzkya adults and larvae can be found in breeding galleries of bark beetles; dauer juveniles of the nematodes can be isolated from dispersing beetles. Many Micoletzkya species are cultured using bacteria; some species can be cultured using C. elegans and other nematodes as food. At 23 °C, the generation time of Micoletzkya is about 10 days. [3]
Dauer describes an alternative developmental stage of nematode worms, particularly rhabditids including Caenorhabditis elegans, whereby the larva goes into a type of stasis and can survive harsh conditions. Since the entrance of the dauer stage is dependent on environmental cues, it represents a classic and well studied example of polyphenism. The dauer state is given other names in the various types of nematodes such as ‘diapause’ or ‘hypobiosis’, but since the C. elegans nematode has become the most studied nematode, the term ‘dauer stage’ or 'dauer larvae' is becoming universally recognised when referring to this state in other free-living nematodes. The dauer stage is also considered to be equivalent to the infective stage of parasitic nematode larvae.
Caenorhabditis is a genus of nematodes which live in bacteria-rich environments like compost piles, decaying dead animals and rotting fruit. The name comes from Greek: caeno- ; rhabditis = rod-like. In 1900, Maupas initially named the species Rhabditis elegans, Osche placed it in the subgenus Caenorhabditis in 1952, and in 1955, Dougherty raised Caenorhabditis to the status of genus.
Androdioecy is a reproductive system characterized by the coexistence of males and hermaphrodites. Androdioecy is rare in comparison with the other major reproductive systems: dioecy, gynodioecy and hermaphroditism. In animals, androdioecy has been considered a stepping stone in the transition from dioecy to hermaphroditism, and vice versa.
Diplogasterida was an order of nematodes. It was sometimes placed in a monotypic subclass Diplogasteria, but molecular phylogenetic evidence has shown it to be embedded in the family Rhabditidae. The confusion of having a hierarchical nesting of groups that were formerly mutually exclusive has led to a profusion of names. Although completely revised taxonomy of nematodes that builds on recent classification systems as well as recent phylogenetic evidence is still necessary, most contemporary taxonomic studies now treat all groups listed under "Diplogasterina" below as a single family, Diplogastridae.
Bursaphelenchus is a genus of nematodes (roundworms) in the order Aphelenchida. Most are obligate mycophages, but some feed on wood, with two species, the red ring nematode and the pine wood nematode, economically significant as pests of coconut palms and of pine trees, respectively. Given that Bursaphelenchus species are usually hard to distinguish from one another except by trained nematologists with access to microscopes or DNA sequence analysis, the entire genus is put under quarantine in some countries. Where this is not the case however, these nematodes are becoming established as model organisms for nematode developmental biology, ecology and genetics.
Ralf Josef Sommer is a German biologist specializing in evolutionary developmental biology.
Caenorhabditis japonica is a species of nematodes in the genus Caenorhabditis. Its genome was sequenced by the McDonnell Genome Institute at Washington University School of Medicine. This gonochoristic species is found in the 'Japonica' group, the sister clade to the 'Elegans' group, in the 'Elegans' supergroup.
Diplogastridae, formerly Diplogasteridae, are a family of nematodes (roundworms) known from a wide range of habitats, often in commensal or parasitic associations with insects.
Pristionchus is a genus of nematodes (roundworms) in the family Diplogastridae that currently includes more than 50 described species. They are known mainly as non-parasitic associates of insects, especially beetles, while others have been reported from soil, organic matter, or rotting wood. The genus includes P. pacificus, a satellite model organism to the well-studied nematode Caenorhabditis elegans.
Pristionchus pacificus is a species of free-living nematodes (roundworms) in the family Diplogastridae. The species has been established as a satellite model organism to Caenorhabditis elegans, with which it shared a common ancestor 200–300 million years ago. The genome of P. pacificus has been fully sequenced, which in combination with other tools for genetic analysis make this species a tractable model in the laboratory, especially for studies of developmental biology.
Pristionchus maxplancki is a species of diplogastrid nematodes (roundworms).
Formicodiplogaster is an extinct form genus of nematodes in the family Diplogasteridae which currently includes a single described species Formicodiplogaster myrmenema. The species is known from early Miocene fossils found on Hispaniola. F. myrmenema has been preserved in association with Azteca alpha, one of only two known fossil species in the ant genus Azteca.
Sudhausia is a genus of nematodes (roundworms) of the family Diplogastridae. They live in association with dung beetles and are primarily known from Africa. Species of Sudhausia show a suite of biological features that, together, are unusual for nematodes and animals in general: hermaphrodites, which are females in form, mature to produce offspring before they are adults and thus even capable of mating, and their eggs grow in size during development. Hermaphrodites are also always live-bearing, which is unusual for nematodes under non-stressful conditions. The genus is named in honor of Walter Sudhaus, a German nematologist.
Levipalatum texanum is a free-living nematode (roundworm) in the family Diplogastridae. The species is androdioecious, consisting of self-fertile hermaphrodites which are morphologically females, and males. It is known from the south-eastern United States and has been found to live in association with scarab beetles, although it has also been baited from soil. Nematodes of this species can be cultured on bacterium Escherichia coli in the laboratory, and they are presumed to also feed on microorganisms in the wild. Levipalatum is a monotypic genus.
Caenorhabditis angaria is a small nematode, in the same genus as the model organism Caenorhabditis elegans. The name is from the Latin after the tendency to ride weevils. Prior to 2011, the species was referred to as C. sp. 2, C. sp. 3, and C. sp. PS1010. Its genome was sequenced at the California Institute of Technology in 2010. This species is gonochoristic. It has distinct morphology and behavior compared to C. elegans; notably, C. angaria males exhibit a spiral mating behavior. Its divergence from C. elegans is similar to the distance between humans and fish. C. castelli is its closest relative, and the two species can produce F1 hybrids.
Pristionchus borbonicus is a species of free-living nematodes (roundworms) in the family Diplogastridae. The species was described from Réunion Island, and is notable for developing one of five different mouth forms depending on available food sources. Pristionchus borbonicus and related species have symbiotic relationships with fig plants and their pollinator wasps.
Myolaimidae is a family of nematodes in the order Rhabditida. It consists of two genera, Myolaimus and Deleyia.
Allodiplogaster sudhausi is a free-living nematode species in the Diplogastridae family. It was described in 2008 as Koerneria sudhausi, before being moved to the genus Allodiplogaster in 2014. A. sudhausi is omnivorous. It predates on other nematodes, but can be cultured on Escherichia coli OP50 bacterium on agar.
Allodiplogaster is a genus of nematodes (roundworms) in the family Diplogastridae that currently includes about 35 described species.
Mononchoides is a genus of nematodes belonging to the family Diplogastridae.