Plasmodium is a genus unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of Plasmodium species involve development in a blood-feeding insect Mode of asexual reproduction in plasmodium which then injects parasites into a vertebrate host during a blood meal. Parasites grow within a vertebrate body tissue often the Mode of asexual reproduction in plasmodium before entering the bloodstream to infect red blood cells.
The ensuing destruction of host red blood cells can result in disease, called malaria. During this infection, some parasites are picked up by a blood-feeding insect, continuing the life cycle. Mode of asexual reproduction in plasmodium is a member of the phylum Apicomplexaa large group of parasitic eukaryotes.
Within Apicomplexa, Plasmodium is in the Mode of asexual reproduction in plasmodium Haemosporida and family Plasmodiidae. Over species of Plasmodium have been described, many of which have been subdivided into 14 subgenera based on parasite morphology and host range. Evolutionary relationships among different Plasmodium species do not always follow taxonomic boundaries; some species that are morphologically similar or infect the same host turn out to be distantly related.
Species of Plasmodium are distributed globally wherever suitable hosts are found. Insect hosts are most frequently mosquitoes of the genera Culex and Anopheles. Vertebrate hosts include reptiles, birds, and mammals. Plasmodium parasites were first identified in the late 19th century by Charles Laveran. Over the course of the 20th century, many other species were discovered in various hosts and classified, including five species that regularly infect humans: A number of drugs have been developed to treat Plasmodium infection; however, the parasites have evolved resistance to each drug developed.
The genus Plasmodium consists of all eukaryotes in the phylum Apicomplexa that both undergo the asexual replication
Mode of asexual reproduction in plasmodium of merogony inside host red blood cells
Mode of asexual reproduction in plasmodium produce the crystalline pigment hemozoin as a byproduct of digesting host hemoglobin. The Plasmodium genome is separated into 14 chromosomes contained in the nucleus. Plasmodium parasites maintain a single copy of their genome through much of the life cycle, doubling the genome only for a brief sexual exchange within the midgut of the insect host.
Proteins are trafficked from the ER to the Golgi apparatus which generally consists of a single membrane-bound compartment in Apicomplexans. Like other apicomplexans, Plasmodium species have several cellular structures at the apical end of the parasite that serve as specialized organelles for secreting effectors into the host. The most prominent are the bulbous rhoptries which contain parasite proteins involved in invading the host cell and modifying the host once inside. Species of Plasmodium
Mode of asexual reproduction in plasmodium contain two large membrane-bound organelles of endosymbiotic originthe mitochondrion and the apicoplastboth of which play key roles in the parasite's metabolism.
Unlike mammalian cells which contain many mitochondria, Plasmodium cells contain a single large mitochondrion that coordinates its division with that of the Plasmodium cell.
The life cycle of Plasmodium involves several distinct stages in the insect and vertebrate hosts. Parasites are generally introduced into a vertebrate host by the bite of an insect host generally a mosquito, with the exception of some Plasmodium species of reptiles.
After emerging from the liver, they enter red blood cells, as explained above. They then go through continuous cycles of erythrocyte infection, while a small percentage of parasites differentiate into a sexual stage called a gametocyte which is picked up by an insect host taking a blood meal.
In some hosts, invasion of erythrocytes by Plasmodium species can result in disease, called malaria. This can sometimes be severe, rapidly followed by death of the host e. In other hosts, Plasmodium Mode of asexual reproduction in plasmodium can apparently be asymptomatic.
Within the red blood cells, the merozoites grow first to a ring-shaped form and Mode of asexual reproduction in plasmodium to a larger form called a trophozoite. Trophozoites then mature to schizonts which divide several times to produce new merozoites. The infected red blood cell eventually bursts, allowing the new merozoites to travel within the bloodstream to infect new red blood cells. Most merozoites continue this replicative cycle, however some merozoites upon infecting red blood cells differentiate into male or female sexual forms called gametocytes.
These gametocytes circulate in the blood until they are taken up when a mosquito feeds on the infected vertebrate host, taking up blood which includes the gametocytes. In the mosquito, the gametocytes move along with the blood meal to the mosquito's midgut.
Here the gametocytes develop into male and female gametes which fertilize each other, forming a zygote. Zygotes then develop into a motile form called an ookinetewhich penetrates the wall of the midgut. Upon traversing the midgut wall, the ookinete embeds into the gut's
Mode of asexual reproduction in plasmodium membrane and develops into an oocyst. Oocysts divide many times Mode of asexual reproduction in plasmodium produce large numbers of small elongated sporozoites.
These sporozoites migrate to the salivary glands of the mosquito where they can be injected into the blood of the next host the mosquito bites, repeating the cycle. Plasmodium belongs to the phylum Apicomplexaa taxonomic group of single-celled parasites with characteristic secretory organelles at one end of the cell. The Plasmodium consists of over species, generally described on the basis of their appearance in blood Mode of asexual reproduction in plasmodium of Mode of asexual reproduction in plasmodium vertebrates.
Species infecting monkeys and apes the higher Mode of asexual reproduction in plasmodium with the exceptions of P. Parasites infecting other mammals including lower primates lemurs and others are classified in the subgenus Vinckeia.
The five subgenera Novyella contain Mode of asexual reproduction in plasmodium known avian malarial species.
AsiamoebaCarinamoebaLacertamoebaOphidiellaParaplasmodiumand Sauramoeba contain Mode of asexual reproduction in plasmodium diverse groups of parasites found to infect reptiles.
More recent studies of Plasmodium species using molecular methods have implied that the group's evolution has not perfectly followed taxonomy. Estimates for when different Plasmodium lineages diverged have differed broadly. Estimates for the diversification of the order Haemosporida range from around For this, estimated range fromto 2.
All Plasmodium species are parasitic and must between a vertebrate host and an insect host to complete their life cycles. Plasmodium parasites have been described in a broad array of vertebrate hosts including reptiles, birds, and mammals. Humans are primarily infected by five species of Plasmodiumwith the overwhelming majority of severe disease and death caused by Plasmodium falciparum. Some of these can cause severe disease in primates, while others can remain in the host for prolonged periods without causing disease.
Again, some species of Plasmodium can cause severe disease in some of these hosts, while many appear not to. Over species of Plasmodium infect a broad variety of birds. In general each species of Plasmodium infects one to a few species of birds. Species from several subgenera of infect diverse reptiles.
Plasmodium parasites have been described in most lizard families and, like avian parasites, are spread worldwide. A number of drugs have been developed over the years to control Plasmodium infection in vertebrate hosts, particularly in humans. Quinine was used as a frontline Mode of asexual reproduction in plasmodium from the 17th century until widespread resistance emerged in the early 20th century.
In addition to a vertebrate host, all Plasmodium species also infect a bloodsucking insect host, generally a mosquito although some reptile-infecting parasites are transmitted by sandflies.
Mosquitoes of the genera CulexAnophelesCulisetaMansonia and Aedes act as insect hosts for various Plasmodium species. The best studied of these are the Anopheles mosquitoes which host the Plasmodium parasites of human malaria, as well as Culex mosquitoes which host the Plasmodium species that cause malaria in birds. Only female mosquitoes are infected with Plasmodiumsince only they feed on Mode of asexual reproduction in plasmodium blood of vertebrate hosts.
Sometimes, insects infected with Plasmodium have reduced lifespan and reduced ability to produce offspring. Plasmodium was first identified when Charles
Mode of asexual reproduction in plasmodium Alphonse Laveran described parasites in the blood of malaria patients in This was followed by the recognition of other two species of Plasmodium which infect humans: Plasmodium ovale and Plasmodium knowlesi identified in long-tailed macaques in ; in humans in InCyril Garnham proposed separating Plasmodium into nine subgenera based on host specificity and parasite morphology.
Telford in when he reclassified Plasmodium parasites that infect reptiles, adding five subgenera. Valkiunas reclassified the bird-infecting Plasmodium species adding a fifth subgenus: From Wikipedia, the encyclopedia. For the multinucleate stage of some microorganisms, see plasmodium life cycle. Instead multiple species of the genus are referred to as " Plasmodium species". Centers for Disease Control and Prevention.
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