Is Ophiocordyceps unilateralis a species complex?
Abstract Ophiocordyceps unilateralis (Ascomycota: Hypocreales) is a specialized parasite that infects, manipulates and kills formicine ants, predominantly in tropical forest ecosystems. We have reported previously, based on a preliminary study in remnant Atlantic Forest in Minas Gerais (Brazil), that O. unilateralis represents a species complex.
Who discovered Cordyceps unilateralis?
Petch (1931) Cordyceps unilateralis (Tul.) Sacc. (1883) Ophiocordyceps unilateralis is an insect-pathogenic fungus, discovered by the British naturalist Alfred Russel Wallace in 1859, and currently found predominantly in tropical forest ecosystems.
What are the hosts of Ophiocordyceps unilateralis?
Ophiocordyceps unilateralis have a pan-tropical distribution. They utilize the local carpenter ant species as their hosts, all of which fall within the tribe Camponotini (which include the genera Camponotus, Polyrachis, and Echinopla) .
Is Oedipus unilateralis a species complex?
We have reported previously, based on a preliminary study in remnant Atlantic Forest in Minas Gerais (Brazil), that O. unilateralisrepresents a species complex.
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Is Ophiocordyceps a parasite?
Like other fungi pathogenic to insects in the genus Ophiocordyceps, the fungus targets a specific host species, Camponotus leonardi; despite this, the fungus may parasitize other closely related species of ants with lesser degrees of host manipulation and reproductive success.
What type of parasite is Ophiocordyceps unilateralis?
Ophiocordyceps unilateralis (Clavicipitaceae: Hypocreales), also referred to as a “zombie fungus,” is a fungal pathogen considered specific to ants of the tribe Camponotini (Formicinae: Formicidae). This entomopathogen currently found predominantly in tropical forest ecosystems9.
Is Ophiocordyceps unilateralis a pathogen?
Background: Ophiocordyceps unilateralis (Clavicipitaceae: Hypocreales) is a fungal pathogen specific to ants of the tribe Camponotini (Formicinae: Formicidae) with a pantropical distribution.
What parasite causes zombie ants?
For the first time, scientists have an image of what happens inside an ant's brain when it is infected with a parasitic worm. Dicrocoelium dendriticum (or the lancet liver fluke) is a parasitic flatworm.
Which fungi are parasites?
Parasitic fungi that live on animals are called zoo-pathogenic fungi. These fungi cause various diseases such as ringworm, favus, epidermophytosis and tinea versicolor. Fungi from the genera Candida are known to cause mycoses of the skin, nails, mucous membranes and other parts of the body.
What happens if you eat Cordyceps?
Cordyceps is said to help fight inflammation in the body. Although some inflammation is good, too much can lead to diseases like heart disease and cancer. Research has shown that when human cells are exposed to Cordyceps, special proteins that increase inflammation in the body become suppressed ( 39 , 40 , 41 , 42 ).
Can Cordyceps infect humans?
Luckily, we don't need to worry about this sort of thing happening to us. Cordyceps can't infect humans, as our bodies are better than insects at attacking pathogens. So you can rest easy, knowing you won't turn into a zombie from these things.
What causes zombie insects?
The Ophiocordyceps unilateralis fungus infects Camponotus leonardi ants that live in tropical rainforest trees. Once infected, the spore-possessed ant will climb down from its normal habitat and bite down, with what the authors call a "death grip" on a leaf and then die.
Can Cordyceps infect animals?
Nope, in the real world a single variety of cordyceps fungus target a single species of insect. So a human-targeting cordyceps fungus wouldn't cause harm to any other plant or animal.
Can ants carry parasites?
Ants can also serve as hosts of a variety of internal or external parasitic nematodes from several families with more or less complex life cycles.
Do ants have parasites?
Social parasites like P. breviceps are social insects that parasitize colonies of other social insects. These parasites are found throughout the social Hymenoptera (i.e., bees, wasps and ants), and have been most intensely studied in ants.
What happens if a zombie ant bites you?
The fungus is not harmful to humans. The article, published in the peer-reviewed Journal of Experimental Biology, said that that results in a death grip. Ants infected by the fungus climb to elevated places and bite onto vegetation, becoming permanently affixed, the team found.
What can Ophiocordyceps unilateralis infect?
Ophiocordyceps unilateralis (Ascomycota: Hypocreales) is a specialized parasite that infects, manipulates and kills formicine ants, predominantly in tropical forest ecosystems.
Is Cordyceps a fungus?
C. Sinensis is an annual Ascomycetes fungus closely related to the mushroom. Although not actually a mushroom taxonomically, it has been described as an exotic medicinal mushroom in traditional Chinese and Tibetan medicine. The name cordyceps comes from Latin words meaning club and head.
How does Ophiocordyceps unilateralis work?
The Ophiocordyceps unilateralis fungus has just one goal: self-propagation and dispersal. Researchers think the fungus, found in tropical forests, infects a foraging ant through spores that attach and penetrate the exoskeleton and slowly takes over its behavior.
How does Ophiocordyceps unilateralis reproduce?
Stroma then begins to grow from the ant head, and the hyphae turn brown (characteristic of Ophiocordyceps unilateralis). One to two weeks after the ant's death, the fungus transitions to sexual reproduction. A unilateral perithecial plate develops on the stroma, which then releases sexual spores.
Why is ophiocordyceps unilateralis an active secondary metabolism?
Ophiocordyceps unilateralis and related species are known to engage in an active secondary metabolism, among other reasons, for the production of substances active as antibacterial agents that protect the fungus-host ecosystem against further pathogenesis during fungal reproduction.
What is the scientific name of the fungus Ophiocordyceps unilateralis sensu lato?
Ophiocordyceps unilateralis sensu lato. The fungus' scientific name is sometimes written as Ophiocordyceps unilateralis sensu lato , which means 'in the broad sense', because the species actually represents a complex of many species within O. unilateralis. Support for this term has become increasingly important.
What is the name of the fungus that infects ants?
Petch (1931) Cordyceps unilateralis (Tul.) Sacc. (1883) Ophiocordyceps unilateralis is an insect-pathogenic fungus, discovered by the British naturalist Alfred Russel Wallace in 1859, and currently found predominantly in tropical forest ecosystems. O. unilateralis infects ants of the tribe Camponotini, with the full pathogenesis being characterized ...
How does O. unilateralis affect host species?
unilateralis on host have been found to vary according to host species. The ant species which are normally found infected in nature exhibit a manipulated behavior, whereas the species which are not typically infected are killed by the infection, but their behaviour is not altered. This is likely due to the heterogeneous nature of the fungus which secretes different metabolites according to host species.
Why do O. unilateralis species have morphological variations?
O. unilateralis species exhibit morphological variations which are most certainly due to their wide geographic range, from Japan to the Americas. Moreover, it has been hypothesized that their morphological variations may also be a result of one fungus species maximizing its infection on one specific host ant species (host-specific infections). Different subspecies of ant can occur within the same area, which means that in order to coexist they have to occupy different ecological niches. Consequently, the fungi may have evolved at the subspecies level in order to maximize its fitness.
How does O. unilateralis manipulate ants?
Studies have shown that O. unilateralis reacts heterogeneously by secreting different metabolites according to the host tissue it encounters and whether they are live or dead. The identification of these natural products is important in order to understand which aspects of the ants are under control and consequently how O. unilateralis manipulates the ant.
Why do parasites manipulate their host?
Some parasites have evolved to manipulate their host's behavior in order to increase their transmission to uninfected susceptible individuals, thereby increasing their fitness. This host manipulation is termed the "extended phenotype" of the parasite and is a form of adaptation. Host ant manipulation by O. unilateralis represents one of the best-known examples of extended phenotypes.
What is the name of the parasite that kills formicine ants?
Ophiocordyceps unilateralis (Ascomycota: Hypocreales) is a specialized parasite that infects, manipulates and kills formicine ants, predominantly in tropical forest ecosystems.
What is the keystone species for unraveling ecosystem functioning and biodiversity of fungi in tropical forests?
Ophiocordyceps unilateralis: A keystone species for unraveling ecosystem functioning and biodiversity of fungi in tropical forests? Ophiocordyceps unilateralis (Ascomycota: Hypocreales) is a specialized parasite that infects, manipulates and kills formicine ants, predominantly in tropical forest ecosystems. We have reported previously, based on ...
How do ophiocordyceps unilateralis live?
The first is ascospore formation and germination, where ascospores are deposited on the hopeless ants and a projection called a germ tube goes into the insect [7]. The ascospores are around 20-100 um in length, and skinny. The second phase is the yeast-like phase, where eventually a mycelium is made [7]. The cells start off looking like individual yeast cells, which then come together to branch out, forming the mycelium (a common structure among fungi). The third phase involves penetration of the insect's cuticle by the newly formed stalk to sporulate and begin the process of infecting more ants [7].
What are the chemicals in Ophiocordyceps unilateralis?
Six different derivatives of naphthoquinones were found in O. unilateralis —deoxyerythrostominol, erythrostominone, epierythrostominol, deoxyerythrostominone, 4-O-methyl erythrostominone, and 3,5,8-trihydroxy-6-methoxy-2- (5-oxohexa-1,3-dienyl)-1,4-naphthoquinone [11]. All six exhibit mild biological impedance of the parasite Plasmodium falciparum, yet 3,5,8-trihydroxy-6-methoxy-2- (5-oxohexa-1,3-dienyl)-1,4-naphthoquinone (TMON) is the only one known to be non-toxic to cells [11]. As well as their antimalarial properties, naphthoquinones such as these have historically been used for colorants in cosmetics due to their natural pigment [11]. Until recently, the assessment of how these chemicals were produced was never explored, but then Prathumpai ‘’et al.’’ came to the rescue. Prathumpai et al. showed that the most favorable metabolite for production of these naphthoquinone species was glucose, and 2.21 g/L/day was consumed by the fungus O. unilateralis, yet the fungus grew very slowly [11]. Because of the glucose finding, and the fact that the highest acetate levels produced from metabolism was on glucose medium, Prathumpai et al concluded that glucose was probably the primary metabolite for the 6 naphthoquinones found. Maltose was found to be the second-best metabolite medium for naphthoquinone production, although it had the highest growth rate [11]. As for the best nitrogen sources for maximum naphthoquinone production, ammonium sulfate was observed to beat out all the other tested nitrogenous sources [11]. This study helped to establish the growth medium necessities for future more efficient large-scale production of these naphthoquinone derivatives produced by O. unilateralis: glucose and ammonium sulfate.
How does O. unilateralis affect the ant?
unilateralis causes the mandibles of the ant to close upon the leaf vein, it begins to atrophy the striated muscle by destroying the sarcomere connections in the muscle fibers, as well as reducing the density of mitochondria and sarcoplasmic reticula [6]. The reduction in mitochondria lowers the amount of energy available to the mandible muscles and eliminates the ability for the muscle fibers to relax and contract, resulting in the permanent closure of the mandibles on the leaf vein (known as the death grip). This action is essential in ensuring that O. unilateralis remains at the proper height above the forest floor for the next steps of fungal development and spore release. Within 24 hours of death, hyphae are seen growing from a number of areas on the ant. Hyphae that protrude from the tarsae of the ants function to secure the ant to the leaf. As the hyphae begin to collect and mass together, stroma can be seen forming at the intersegmental membrane at the base of the ant’s head around the 2 day mark. [10]
What is the name of the fungus that kills formicine ants?
Ophiocordyceps unilateralis (Ascomycota: Hypocreales) is a specialized fungal parasite that infects, manipulates and kills formicine ants, predominantly in tropical forest ecosystems. It specifically infects Camponotus leonardi of the tribe of campotini [3, 2].
What is the most interesting fact about O. unilateralis?
unilateralis is that it has the ability to take the body of an ant captive, turning it into a so-called "zombie ant" and manipulating its psychomotor functions via the release of toxins [2].
Is O. unilateralis a fungus?
As O. unilateralis is an entomopathogenic fungus, it's metabolism involves cellular processes based on the decomposition of the ant's body. The exoskeleton remains intact, however the innards of the ant are eventually consumed by the infection of the O. unilateralis yeast-like cell phase [7].
Is the genome of O. unilateralis sequenced?
Genome Structure. The genome of this organism is not sequenced entirely, although major enzymes such as RNA polymerases have been sequenced. Four polyketide synthase (PKS) genes have been found in O. unilateralis [8].
How many species of O. unilateralis are there?
Image via Tommy Leung. 6. Scientists have discovered 200 species of O. unilateralis that can infect a variety of species from spiders to caterpillars (Lu, 2019) Image shows various Cordyceps species infecting a range of hosts.
What is the name of the parasite that infects and manipulates formicine ants?
Written by: Daksh Verma, Richard Xu, Caleb Ng, Jeffrey Lu, Carmen Chau. 1. Ophiocordyceps unilateralis ( also known as the “zombie ant fungus”) is a fungal parasite that infects and manipulates formicine ants to achieve its only goal: Reproduction by dispersal (Lu, 2019). This fungus usually infects ants of the Camponotini tribe.
What is the O. sinensis?
9. The O. sinensis (another fungus of the same class as the O. unilateralis) is used as a type of traditional medicine in China. There has been research into whether the O. unilateralis can also be used for medicinal purposes (Kumlien & Carlson, 2006).
What is the parasitic fungus in The Last of Us?
In the The Last of Us video game series, the parasitic fungus that causes the infection that turns the United States into a post-apocalyptic world is a fictional mutant strain of O. unilateralis (Kumlien & Carlson, 2006).
What tribe is the orange bulb from?
This fungus usually infects ants of the Camponotini tribe. There are approximately 1.5 million species of this fungus, however less than 100,000 have been described (Evans, Elliot, & Hughes, 2011). Image of a dead ant with O. unilateralis growing out of the base of its head. The orange bulb contains spores that are released to infect more ants.
What does "ophiocordyceps unilateralis sensu lato" mean?
The scientific name is sometimes written Ophiocordyceps unilateralis sensu lato, which means “in the broad sense”. This is because the species is actually a complex of many species within O. unilateralis.
Why is O. unilateralis important?
unilateralis and related species are known to engage in an active secondary metabolism, among other reasons, for the production of substances active as antibacterial agents that protect the fungus-host ecosystem against further pathogenesis during fungal reproduction. Because of this secondary metabolism, an interest in the species has been taken by natural products chemists, with corresponding discovery of small molecule agents (e.g. of the polyketide family) of potential interest for use as human immunomodulatory, antiinfective, and anticancer agents.
What is the fungus that parasitizes ants?
Like other fungi pathogenic to insects in the Ophiocordyceps genus, O. unilateralis targets a specific host species, the Camponotus leonardi ant. However, the fungus may parasitize other closely related species of ants with lesser degrees of host manipulation and reproductive success. The spores of the fungus attach to the ant, ...
What is the fungus that infects ants?
Ophiocordyceps unilateralis is an entomopathogen, or insect-pathogenising fungus, discovered by the British naturalist Alfred Russel Wallace in 1859, and currently found predominantly in tropical forest ecosystems. O. unilateralis, also referred to as a zombie fungus, infects ants of the Camponotini tribe, with the full pathogenesis being characterized by alteration of the behavioral patterns of the infected ant. Infected hosts leave their canopy nests and foraging trails for the forest floor, an area with a temperature and humidity suitable for fungal growth; they then use their mandibles to affix themselves to a major vein on the underside of a leaf, where the host remains until its eventual death. The process leading to mortality takes 4–10 days, and includes a reproductive stage where fruiting bodies grow from the ant’s head, rupturing to release the fungus’s spores. O. unilateralis is in turn also susceptible to fungal infection itself, an occurrence which can limit its impact on ant populations, which has otherwise been known to devastate ant colonies.
What is the fungus that contains metabolites?
The Ophiocordyceps fungus contains various known metabolites, as well as a number of structurally uncharacterized substances; these natural products are reportedly being investigated as potential leads in discovery efforts toward immunomodulatory, antitumor, hypoglycemic, and hypocholesterolemic targets.
Is O. unilateralis a fungus?
unilateralis is very virulent, only about 6.5% of all fruiting bodies are viable spore-producers. This is caused by the castration of the fungus by the hyperparasite, which may cause the limiting of the viable infectious spores.
Is O. unilateralis a fungal hyperparasite?
O. unilateralis suffers from an unidentified fungal hyperparasite, reported in the lay press as the “anti-zombie-fungus fungus”, that results in only 6–7% of sporangia being viable, limiting the damage O. unilateralis inflicts on ant colonies.
What is the name of the parasite that kills formicine ants?
Ophiocordyceps unilateralis (Ascomycota: Hypocreales) is a specialized parasite that infects, manipulates and kills formicine ants, predominantly in tropical forest ecosystems. We have reported pre...
What is the keystone species for unraveling ecosystem functioning and biodiversity of fungi in tropical forests?
Ophiocordyceps unilateralis: A keystone species for unraveling ecosystem functioning and biodiversity of fungi in tropical forests?
How many species of ophiocordyceps are there?
In all, researchers have identified over 200 species of Ophiocordyceps that can infect hosts from 10 insect orders, as well as spiders, though not all lead to behavioral manipulation. One related species, O. sinensis, colonizes ghost moth caterpillars and erupts from their head like a unicorn horn.
What episode of Hostile Planet is the parasite?
The deadly parasite’s grand finale involves sending toxic spores blooming from the dead ant’s head. Deep in the Amazon rainforest, parasitic fungi called take over ants' bodies in order to reproduce. It's featured in National Geographic Channel's Hostile Planet episode on jungles, airing Monday, April 22 at 9 p.m. EST.
What does Entomophthora muscae mean?
Scientists do know of a few though. There’s Entomophthora muscae, which literally means “insect destroyer of the fly” in Greek. It causes infected flies to climb a certain height, glue themselves at the mouth to a plant, and assume an abdomen-up “death pose” that’s optimal for spore dispersal.
Do insects have fungal organisms?
Much like the microbiome in our own guts, insects contain a whole array of fungal species, says Barrett Klein, an entomologist at the University of Wisconsin in La Crosse. But because not all fungi can be grown in the lab, only a couple have been closely studied, much less flagged for causing behavioral manipulations.
Does Ophiocordyceps unilateralis invade the brain?
And perhaps in the biggest deviation from the zombie playbook, Ophiocordyceps unilateralis don’t seem to invade the brain.
Overview
Parasite adaptation
In host–parasite dynamics, both the host and the parasite are under selective pressure: the parasite evolves to increase its transmission, whereas the host evolves to avoid and/or resist the infection by the parasite.
Some parasites have evolved to manipulate their host's behavior in order to increase their transmission to uninfected susceptible individuals, thereby increasing their fitness. This host m…
Systematics
After years of research, the taxonomy of Ophiocordyceps unilateralis is becoming increasingly clear.
Throughout history there has been confusion about the distinction between the genera Cordyceps and Ophiocordyceps. There have been many debates about whether the zombie-ant fungus (and other fungi) belonged to one or to the other as Ophiocordyceps was only recently brought forward.
Morphology
The zombie-ant fungus is easily identifiable when its reproductive structure becomes apparent on its dead host, usually a carpenter ant. At the end of its life cycle, O. unilateralis typically generates a single, wiry yet pliant, darkly pigmented stroma which arises from the dorsal pronotum region of the ant once it is dead. Moreover, perithecia, the spore-bearing sexual structure, can be obs…
Life cycle
In tropical forests, the ant species Camponotus leonardi lives in the high canopy and has an extensive network of aerial trails. Sometimes the canopy gaps are too difficult to cross, so the ants' trails descend to the forest floor where they are exposed to O. unilateralis spores. The spores attach to their exoskeletons and eventually break through using mechanical pressure and enzymes. Like other fungi pathogenic to insects in the genus Ophiocordyceps, the fungus target…
Natural products
O. unilateralis' life cycle includes and depends on the infection and the manipulation of a carpenter ant, principally C. leonardi. The behavioral manipulation of the ant, which gives rise to the name "zombie-ant", is an extended phenotype of the fungus. It first affects the ant's behavior through convulsions that make it fall from its high canopy nest onto the forest floor. Th…
Geographic distribution
Many studies describe Ophiocordyceps unilateralis distribution as pantropical since it occurs mainly in tropical forest ecosystems. However, there are some reports of the zombie-ant fungus in warm-temperate ecosystems.
Its distribution includes tropical rainforests located in Brazil, Australia and Thailand, and temperate forests found in South Carolina, Florida and Japan.
Host impact
When O. unilateralis-infected ants die, they are mainly located in regions containing a high density of ants which were previously manipulated and killed. These areas are termed "graveyards" and can be of 20 to 30 meters in range (with a local density of dead ants possibly exceeding 25 meters square).
The density of dead ants within these graveyards can vary according to climatic conditions. Thi…
Classification
Description and Significance
- Ophiocordyceps unilateralis (Ascomycota: Hypocreales) is a specialized fungal parasite that infects, manipulates and kills formicine ants, predominantly in tropical forest ecosystems. It specifically infects Camponotus leonardiof the tribe of campotini [3, 2]. Worker ants are infected during foraging when the fungal spores attach to their cuticles ...
Genome Structure
- The genome of this organism is not sequenced entirely, although major enzymes such as RNA polymerases have been sequenced. Four polyketide synthase (PKS) genes have been found in O. unilateralis. PKS enzymes synthesize polyketide proteins, which have proven to be novel antibiotics, antifungal agents, and even cholesterol lowering agents . The genome obviously con…
Cell Structure and Metabolism
- There are three distinct phases of life for Ophiocordyceps unilateralis.The first is ascospore formation and germination, where ascospores are deposited on the hopeless ants and a projection called a germ tube goes into the insect . The ascospores are around 20-100 um in length, and skinny. The second phase is the yeast-like phase, where eventually a mycelium is ma…
Ecology
- Ophiocordyceps unilateralis have a pan-tropical distribution. They utilize the local carpenter ant species as their hosts, all of which fall within the tribe Camponotini (which include the genera Camponotus, Polyrachis, andEchinopla) . O. unilateralis is very ecologically driven, with the parasite specializing in specific host species depending on what is common to the area. It has r…
Pathology
- When the spores arrive on their target, host-recognition features cause it to form a “drill,” utilizing mechanical pressures and enzymes to breach the exoskeleton. Once the exoskeleton is breached the fungus goes into a free-living yeast stage in the ant’s hemocoel. It is supposed that once the fungus colonizes the hemocoel, it releases nerve toxins that alter the ants behavior . These nerv…
Current Research
- In 2011, Hughes et al. studied the behavioral and morphological mechanisms of the fungus O. unilateralis . Countless hours of observation of the infected ants' walking patterns resulted in an observed random walking pattern as the research team had predicted, instead of a directed walk . While we now have a better understanding than before about the advanced and complex morph…
Cool Factor
- By far the most interesting fact about the organism O. unilateralisis that it has the ability to take the body of an ant captive, turning it into a so-called "zombie ant" and manipulating its psychomotor functions via the release of toxins . The evidence from fossil samples those taken from the Messel Pit in eastern Germany of leaves from Byttnertiopsis daphnogenes when comp…