| Adeleorina | |
|---|---|
 | |
| Cyst of an unidentified haemogregarine in the liver of a bat | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Diaphoretickes |
| Clade: | SAR |
| Clade: | Alveolata |
| Phylum: | Apicomplexa |
| Class: | Conoidasida |
| Order: | Eucoccidiorida |
| Suborder: | Adeleorina |
| Families | |
Adeleidae Contents | |
Adeleorina is a suborder of parasites in the phylum Apicomplexa. [1]
Léger proposed this taxon in 1911. The first species identified was Dactylosoma ranarum by Lankester (1871) in a frog in Europe. It was initially called Undulina ranarum, but this was changed in 1882 to Drepanidium ranarum. This species was subsequently moved to the genus Dactylosoma.
Canine hepatozoonosis was first described in India in 1905 by James. The organism was named Leukocytozoon canis. The vector was identified in 1907 by Christopher to be the brown dog tick ( Rhipicephalus sanguineus ). The genus Hepatozoon was created by Miller in 1908 for a parasite of the white rat ( Rattus norvegicus ) that underwent merogony in the liver and sporogony in the mite Laelap echidinus . Ledger initially placed this genus in the family Haemogregarinidae, but Wenyon subsequently removed it and placed it in the newly created taxon Hepatozoidae in 1926.
All species in this suborder use the syzygy method of gamete formation. This involves the association of often motile gamonts prior to the formation of functional gametes and fertilization.
Their life cycles tend to be complex, involving at least one (and often several) asexual cycles of merogony followed by gametogony, syngamy and sporogony. In many species of the group, the meronts and merozoites have morphologically distinct types: one type of meront produces large merozoites which initiate a further round of merogonic replication; a second produces smaller merozoites which are the progenitors of the gamonts. Microgamonts produce usually only one to four microgametes. Other characteristic features include the absence of endodyogeny and the enclosure of sporozoites in a sporocyst.
In haemogregarines with heteroxenous species, conjugation of gamonts and subsequent sporogony usually occurs within an invertebrate (definitive host), which also serves as the vector. Merogonial division usually takes place in the parenchymatous organs of the vertebrate host. This is followed by the formation of infective gametocytes in the erythrocytes. In the genus Hepatozoon , gametocytes are also formed in the leukocytes.
The haemogregarines use two modes of transmission:
Adeleorina has about 500 species, which have been organised into seven families and 19 genera. The families have been divided into two groups:
One exception to this classification is known: Klossiella (family Klossiellidae) is a monoxenous coccidium of mammals and reptiles.
The taxonomy is this group may be incorrect as the Hepatozoidae appear to be paraphyletic. [2] The genus Hemolivia appears to lie within the genus Hepatozoon. [3] The genus Hepatozoon appears to have two subgenera with one in the carnivorous mammals and the other in lower vertebrates and rodents. [4]
The families in this suborder are:
Karyolysus infects lizards ( Lacerta ) and possibly scincids. Haemogregarina infects turtles and leeches. Species of the genus Desseria infect fish and lack erythrocytic merogony. The genera in the subfamily Ithaniinae share a number of morphological features and infect the digestive tract of insects.
DNA studies suggest Hemolivia may lie within the Hepatozoon clade. [3] If this can be confirmed, the taxonomy of this group will need revision. A study of the 18s rRNA gene suggests that there may be some overlap between Karyolysus and Hepatozoon. [6]
Karadjian, Chavatte and Landau revised the Adeleidae in 2015, [7] performed a molecular analysis and proposed a new classification in four 'types' based on their biology, as follows:
The Apicomplexa are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of (non-photosynthetic) plastid called an apicoplast—with an apical complex membrane. The organelle's apical shape is an adaptation that the apicomplexan applies in penetrating a host cell.
Coccidia (Coccidiasina) are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida. As obligate intracellular parasites, they must live and reproduce within an animal cell. Coccidian parasites infect the intestinal tracts of animals, and are the largest group of apicomplexan protozoa.
Hepatozoon is a genus of Apicomplexa alveolates which incorporates over 300 species of obligate intraerythrocytic parasites. Species have been described from all groups of tetrapod vertebrates, as well as a wide range of haematophagous arthropods, which serve as both the vectors and definitive hosts of the parasite. By far the most biodiverse and prevalent of all haemogregarines, the genus is distinguished by its unique reciprocal trophic lifecycle which lacks the salivary transmission between hosts commonly associated with other apicomplexans. While particularly prevalent in amphibians and reptiles, the genus is more well known in veterinary circles for causing a tick-borne disease called hepatozoonosis in some mammals.
The gregarines are a group of Apicomplexan alveolates, classified as the Gregarinasina or Gregarinia. The large parasites inhabit the intestines of many invertebrates. They are not found in any vertebrates. Gregarines are closely related to both Toxoplasma and Plasmodium, which cause toxoplasmosis and malaria, respectively. Both protists use protein complexes similar to those that are formed by the gregarines for gliding motility and for invading target cells. This makes the gregarines excellent models for studying gliding motility, with the goal of developing treatment options for both toxoplasmosis and malaria. Thousands of different species of gregarine are expected to be found in insects, and 99% of these gregarine species still need to be described. Each insect species can be the host of multiple gregarine species. One of the most-studied gregarines is Gregarina garnhami. In general, gregarines are regarded as a very successful group of parasites, as their hosts are distributed over the entire planet.
Leucocytozoon is a genus of parasitic alveolates belonging to the phylum Apicomplexa.
Conoidasida is a class of parasitic alveolates in the phylum Apicomplexa. The class was defined in 1988 by Levine and contains two subclasses – the coccidia and the gregarines. All members of this class have a complete, hollow, truncated conoid. Gregarines tend to parasitize invertebrates with the mature gamonts being extracellular; the coccidia mostly infect vertebrates and have intracellular gamonts.
Karyolysus is a genus of coccidia. With the exception of K. sonomae whose vertebrate host is the yellow-legged frog, species in this genus only infect lizards of the genus Lacerta.
Achromatorida is an order of non-pigmented intraerythrocytic parasitic alveolates belonging to the subclass Haemosporidiasina. The order was created by Jacques Euzéby in 1988.
The Haemoproteidae are a family of parasitic alveolates in the phylum Apicomplexa.
Dactylosoma is a genus of parasitic alveolates of the phylum Apicomplexa.
Anthemosoma is a genus of parasites of the phylum Apicomplexa. There is only one species recognised in this genus - a parasite of mammals.
Hemolivia is a genus of the phylum Apicomplexia.
The genus Schellackia comprises obligate unicellular eukaryotic parasites within the phylum Apicomplexa, and infects numerous species of lizards and amphibians worldwide. Schellackia is transmitted via insect vectors, primarily mites and mosquitoes, which take up the parasite in blood meals. These vectors then subsequently infect reptilian and amphibian which consume the infected insects. The parasites deform erythrocytes of the host into crescents, and can be visualized using a blood smear.
The Archigregarinorida are an order of parasitic alveolates in the phylum Apicomplexa. Species in this order infect marine invertebrates — usually annelids, ascidians, hemichordates and sipunculids.
The Caulleryellidae are a family of parasites in the phylum Apicomplexa. Species in this family mostly infect dipteran larvae.
The Schizocystidae are a family of parasitic alveolates in the phylum Apicomplexa. Species in this family infect insects.
Bartazoon is a genus of parasitic alveolates in the phylum Apicomplexa.
Syncystis is a genus of parasitic alveolates in the phylum Apicomplexa.
Schizocystidae is a genus of parasitic alveolates in the phylum Apicomplexa.
Lipocystis is a genus of parasitic alveolates of the phylum Apicomplexa.
