''Nephridiophaga'' 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 ...

of single cell

eukaryotes The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of ...

, now considered to be fungi, that pathogenically inhabit the

Malpighian tubules The Malpighian tubule system is a type of excretory and osmoregulation, osmoregulatory system found in some insects, myriapods, arachnids and tardigrades. It has also been described in some crustacean species, and is likely the same organ as the ...

insects Insects (from Latin ') are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed ...

. Ivanic described the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

species from

honey bee A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to mainland Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the ...

Morphology and life cycle

''Nephridiophaga'' spores are small, flattened ovals that resemble a

red blood cell Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cel ...

. Each spore contains a single nucleus and may have an inconspicuous, central opening. Spores are ingested by insects. Once inside the host, spores germinate, though whether in the gut or elsewhere is not known.

Plasmodia ''Plasmodium'' is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of ''Plasmodium'' species involve development in a blood-feeding insect host which then injects parasites into a verteb ...

inhabit and feed on Malpighian tubule cells where they are in direct contact with the

cytoplasm The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell a ...

. Multi-nucleate plasmodia are eventually released into the lumen, some attach to the brush border of the tubule cells using

pseudopodia A pseudopod or pseudopodium (: pseudopods or pseudopodia) is a temporary arm-like projection of a eukaryotic cell membrane that is emerged in the direction of movement. Filled with cytoplasm, pseudopodia primarily consist of actin filaments and ...

that interdigitate with the

microvilli Microvilli (: microvillus) are microscopic cellular membrane protrusions that increase the surface area for diffusion and minimize any increase in volume, and are involved in a wide variety of functions, including absorption, secretion, cellula ...

of the cells. Other plasmodia form merozoite-like cells. Plasmodia released into the lumen for
sporoblasts
internally with a spore wall enclosing each nucleus. Sporoblasts can be asexual or sexual. Asexual sporoblasts are formed from a type of closed

mitosis Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identic ...

with chromosomes un-condensed and spindle poles remaining un-connected to the nuclear envelope, which is a common form of mitosis for fungi. Sexual sporoblasts are formed after the fusion of

meiotic 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 copy ...

nuclei; however, the details of meiosis and fusion are not known, and the phenomenon is doubted by some authors. Spores are excreted from the insect in its

feces Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...

Taxonomy

''Nephridiophaga'' was originally placed in the

protist A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancest ...

order

Haplosporidia The Ascetosporea are a group of eukaryotes that are parasites of animals, especially marine invertebrates. The two groups, the haplosporids and paramyxids, are not particularly similar morphologically, but consistently group together on molecula ...

, though not all researchers agreed, with some placing it in the

Microsporidia Microsporidia are a group of spore-forming unicellular parasites. These spores contain an extrusion apparatus that has a coiled polar tube ending in an anchoring disc at the apical part of the spore.Franzen, C. (2005). How do Microsporidia inva ...

, and others leaving it unclassified. Molecular phylogenetic studies of species infecting

cockroach Cockroaches (or roaches) are insects belonging to the Order (biology), order Blattodea (Blattaria). About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known Pest (organism), pests. Modern cockro ...

es have shown that the genus belongs in or close to the

Chytrid Chytridiomycota are a division of zoosporic organisms in the kingdom (biology), kingdom Fungi, informally known as chytrids. The name is derived from the Ancient Greek ('), meaning "little pot", describing the structure containing unreleased zo ...

division of the kingdom

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 ...

Species

Based on * '' Nephridiophaga apis'' Ivanić 1937 * '' Nephridiophaga archimandrita'' Radek, Wellmanns & Wolf 2011 * '' Nephridiophaga blaberi'' Radek & Storch 2000 * '' Nephridiophaga blatellae'' (Crawley 1905) Woolever 1966 * '' Nephridiophaga forficulae'' (Léger 1909) Ormières & Manier 1973 * '' Nephridiophaga lucihormetica'' Radek, Wellmanns & Wolf 2011 * '' Nephridiophaga maderae'' Radek et al. 2017 * '' Nephridiophaga meloidorum'' (Purrini & Rohde 1988) Lange 1993 * '' Nephridiophaga ormieresi'' Toguebaye et al. 1986 * '' Nephridiophaga periplanetae'' (Lutz & Splendore 1903) Lange 1933 * '' Nephridiophaga schalleri'' (Pumni & Rohde 1988) Lange 1993 * '' Nephridiophaga tangae'' (Purrini, Weiser & Kohring 1988) Lange 1993 * '' Nephridiophaga xenoboli'' Ganapati & Narasimhamurti 1960

References

{{Taxonbar, from=Q25365866 Chytridiomycota Chytridiomycota genera