''Frenkelia'' is a genus of

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s in the phylum

Apicomplexa The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex structure. Th ...

. The species in this genus infect the gastrointestinal tracts of

birds of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...

(definitive hosts) and the tissues of small

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

s (intermediate hosts).

Taxonomy

Species of this genus share

antigen In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune respons ...

s with ''

Sarcocystis ''Sarcocystis'' is a genus of protozoan parasites, with many species infecting mammals, reptiles and birds. Its name is dervived from Greek ''sarx'' = flesh and ''kystis'' = bladder. The lifecycle of a typical member of this genus involves two ...

''. DNA studies suggest that this genus should be merged with ''Sarcocystis''. Despite several recommendations, abolition of this genus has not yet been approved.

Lifecycle

The parasites undergo sexual reproduction in the gut of the definitive host — a bird of prey. They form cysts and are then eaten by a small rodent. Within the gut of the rodent, the parasites decyst. They invade the intestinal wall and are carried to the

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...

. They undergo schizogony in the

hepatocyte A hepatocyte is a cell of the main parenchymal tissue of the liver. Hepatocytes make up 80% of the liver's mass. These cells are involved in: * Protein synthesis * Protein storage * Transformation of carbohydrates * Synthesis of cholesterol, ...

s and

Kupffer cell Kupffer cells, also known as stellate macrophages and Kupffer–Browicz cells, are specialized cells localized in the liver within the lumen of the liver sinusoids and are adhesive to their endothelial cells which make up the blood vessel walls. Ku ...

s. They then invade the nervous tissue of the rodent host, forming cystic structures. The infected rodent is then eaten by a bird, when the tissue cysts are digested, releasing the parasites. The parasites invade the enterocytes, undergo

merogony Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

and

gametogony Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

. Gametes are formed which then fuse forming a

zygote A zygote (, ) is a eukaryotic cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individual organism. In multicell ...

that undergoes encystation.

Host records

*''Frenkelia microti'' — red tailed hawk ('' Buteo jamaicensis''), chinchilla (''

Chinchilla lanigera The long-tailed chinchilla (''Chinchilla lanigera''), also called the Chilean, coastal, common, or lesser chinchilla, is one of two species of rodent from the genus '' Chinchilla'': the other species being '' C. chinchilla''. Both species are end ...

''), prairie voles ('' Microtus ochrogaster'')

Unknown parasite species

*Field mouse ('' Apodemus flavicollis'') *Water vole ('' Arvicola sapidus'') *Red-tailed hawks ('' Buteo borealis'') *Red-backed vole ('' Clethrionomys rufocanus'') *Porcupine ('' Erethizon dorsatum'') *Muskrat ('' Ondatra zibethica'') *Northern spotted owl ('' Strix occidentalis caurina'')

References

Apicomplexa genera Parasites of birds {{Apicomplexa-stub