Witch trials

Victims of ergotism. Pieter Bruegel painting, Louvre.

Ergot poisoning was certainly common in history, there is no doubt about that. But was it responsible for the events that occurred in Salem and what exactly is the evidence that the fungus was involved?

From The Straight Dope - Were the witches of Salem a result of poisoning with ergot fungus?

In 1976 psychology grad student Linnda R. Caporael proposed the ergotism hypothesis, and history professor Mary Matossian elaborated on it in 1982. The core contentions: A cold winter followed by a moist spring and summer prior to the witchcraft hysteria favored the growth of ergot fungus in rye that the colonists were obliged to eat due to crop failure. Ergot contains toxins known to cause convulsions, hallucinations, and other symptoms similar to those reported by the accusers. 

Doubters were quick to raise objections: Evidence of a cold winter and crop failure is dubious, and none of the accusers displayed the full array of symptoms needed to support a diagnosis of convulsive ergotism. More importantly, the symptoms appeared only at opportune moments during the trials, strongly suggesting a psychosomatic origin if not fraud. The counterarguments seem to have persuaded most historians, but a credulous 2001 PBS documentary has helped keep conjecture about ergotism alive. 

A. Woolf in the Journal of  Clinical Toxicology reaches a similar conclusion. Witchcraft or mycotoxin? The Salem witch trials.

 

The Salem witchcraft trials of 1692 have been studied by many historians looking for the complex social, political, and psychological determinants behind the community-wide hysteria that led to a travesty of justice and the deaths of 20 innocent Puritans. Recently, ergot poisoning has been put forth by some as a previously unsuspected cause of the bizarre behaviors of the young adolescent girls who accused the townsfolk of witchcraft. In this essay the circumstances behind the ergot poisoning theory for this historical event are described. When the evidence is weighed carefully both pro and con, it seems unlikely that ergotism explains much of what went on in colonial Salem.

Read Linnda Caporael's 1976 paper (in Science) and weigh the evidence for yourselves: Ergotism: the satan loosed in Salem?

Schizophyllum commune

I found a very nice little explanation of fungal mating types at the rather splendid Cornell Mushroom Blog:

Among fungi, any individual can donate or receive genetic material–so you can already see we need to let go of the concept of gender. Let’s talk instead in terms of what mycologists call mating types. A fungus simply needs to find a mate of a different mating type. Of the fungi you might be familiar with, hmm, most species have only two mating types (they’re bipolar), and some have four or more possible mating types (they’re tetrapolar). Any particular individual of a species is just one mating type, of course. Most molds have two; many mushrooms and bracket fungi have four or more. A few fungi, like the unassuming split gill, Schizophyllum commune, have more than ten thousand!

 According to Tom Volk at the University of Wisconsin, Schizophyllum commune can have 28,000 different mating strains! It sounds like exactly the same sort of frequency dependent selection that leads to hundreds of self-sterility alleles is responsible.


In Schizophyllum commune there are more than 300 alleles at the A locus and more than 90 known for the B locus. Thus there are more than 28,000 different combinations of A and B, or 28,000 different sexes! Each individual is compatible with 27,997 of the others in the worldwide population (99.98% outbreeding) compared with being compatible with only 1/4 of its siblings. Thus the enormous number of sexes in fungi is meant to encourage non-sibling mating and non-relative mating, which ensures genetic diversity in the population. This seems to have worked quite well in the widely distributed Schizophyllum.

Fungus amongus (or at least among ants)

Here's a recent post from NPR on  'Zombie' Ants And The Fungus That Saves Them",  relevant to John's lecture on crazy fungi.

"In the current edition of the journal PLoS ONE, an international research team led by David Hughes of Penn State University reports that they've found the fungus that allows an ant colony to survive infestations by a "zombie-ant fungus, which invades an ant's brain and causes it to march to its death at a mass grave near the ant colony, where the fungus spores erupt out of the ant's head."

"In a case where biology is stranger than fiction, the parasite of the zombie-ant fungus is itself a fungus — a hyperparasitic fungus that specializes in attacking the parasite that turns the ants into zombies," Hughes said."

In Science Daily, too.  The article will be published shortly in Plos One, but in the meantime here is a link to David Hughes website to learn more about what he is researching.

Fungi everywhere

Okay, well I was inspired to go away and look up some information on cues for fungal spore germination and whether, as living humans, we are not a suitable substrate for most fungi to germinate on or whether we continually fight them off.

In at least one common case it is apparently the latter. Aspergillus fumigatus is a very common saprotrophic fungus and its spores are everywhere. In fact its estimated that everyone breathes in several hundred Aspergillus fumigatus each day. 


We know that the immune system plays a vital role in fighting off this fungus because immunosuppressed individuals are susceptible to invasive A. fumigatus infection. This can take a variety of forms but most commonly manifests as invasive pulmonary aspergillosis. If not dealt with by the innate immune system then inhaled spores germinate in the warm, moist, nutrient-rich environment of the pulmonary alveoli and can lead to chronic pulmonary infections.

We know a lot about the way that our immune system functions to control potentially lethal fungal infections like A. fumigatus - here's one recent review: Immune responses against Aspergillus fumigatus: what have we learned?

Fungi Video

Here's a video I thought was really cool on a group of mycologists.

http://vimeo.com/36422624

"Most people know Kew Gardens as home of the world's largest living plant collection but are not aware that it is also the location of an internationally important botanical research and educational institution. Going beyond the gardens as we know them, Lonelyleap produced two films for 2012's Tropical Extravaganza Festival which showcase the behind the scenes work of Kew's scientists whilst also exploring two of the festival's themes, Earth and Air.

The first in the series explores the importance of fungi to all plants and ultimately all life on Earth through several members of the Mycology Department committed to the conservation and exploration of fungi."

The carpenter ant in the picture on the right (genus Campanotus) has fallen victim to parasitic fungi of the genus Cordyceps, which manipulate the behaviour of their host in order to increase their own chances of reproducing. The spores of the fungus attach themselves to the external surface of the ant, where they germinate. They then enter the ant’s body through the tracheae via holes in the exoskeleton called spiracles. Fine fungal filaments called mycelia then start to grow inside the ant’s body cavity, absorbing the host’s soft tissues but avoiding its vital organs.


When the fungus is ready to sporulate, the mycelia grow into the ant’s brain. The fungus then produces chemicals which act on the host’s brain and alter its perception of pheromones. This causes the ant to climb a plant and, upon reaching the top, to clamp its mandibles around a leaf or leaf stem, thus securing it firmly to what will be its final resting place.


The fungus then devours the ant’s brain, killing the host. The fruiting bodies of the fungus sprout from the ant’s head, through gaps in the joints of the exoskeleton. Once mature, the fruiting bodies burst, releasing clusters of capsules into the air. These in turn explode on their descent, spreading airborne spores over the surrounding area. These spores then infect other ants,completing the life cycle of the fungus. Depending on the type of fungus and the number of infecting spores, death of an infected insect takes between 4-10 days.


Quoted from (click link to learn more): http://neurophilosophy.wordpress.com/2006/11/20/brainwashed-by-a-parasite/

Crytptomycota - a new kingdom

The evolutionary tree of fungi grows a new branch

Fungi found in UK pond could be part of a previously undiscovered — and extremely diverse — phylum.

When a research team started analysing the genetics of microorganisms from their university pond, they might have expected to find a couple of new species. Instead, they discovered a group of fungi that could double the size of that biological kingdom.

Nature news report here and the actual article, Discovery of novel intermediate forms redefines the fungal tree of life, here.

Shoestring rot

The giant fungus I mentioned in class is an individual Armillaria bulbosa, or honey mushroom. I've posted about this study before so check that out for further details on the 'pulsating mass of fungus'.

A subsequent study in Oregon revealed an even larger individual of another species in the same genus, Armillaria ostoyae or 'Shoestring rot' . This fungus attacks the sapwood of a variety of tree species and is able to travel great distances under the bark or between trees in the form of black rhizomes.

A question in class about why individuals are able to get so big is possibly answered by this comment by the author of the study I found on a BBC news report:

The huge size of this fungus may be related to the dry climate in eastern Oregon, Dr Dreisbach said. Spores have a hard time establishing new organisms, making room for the old-timers to spread.

This is the original paper, Coarse-scale population structure of pathogenic Armillaria species in a mixed-conifer forest in the Blue Mountains of northeast Oregon,

..and now for something completely different.

After years of neglect it appears that microbial art is making something of a come back. Because we'll be talking about Fungi tomorrow here's a Fungus made out of bacteria by Niall Hamilton . Hmm, that's just wrong.

For all your microbial art needs there is the MicrobialArt website. You can see more from Niall Hamilton, and many more.
From an interview at MycoRant:

Hamilton uses both fungi and bacteria in his creations, and each no doubt has its own advantages and disadvantages. “I have to say I’m rather envious of other artists’ work with bioluminescent bacteria or slime molds,” he offers, adding, “both of which I think are very visually impressive. But, I haven’t had the opportunity to work with them (simply because I haven’t isolated them). Bacteria I like for the fast growth and clean edges, but they generally are a lot more limited in range of color and texture than the fungi.”

Biomechanics of Fungi

Here's an interesting paper from PNAS at the end of last year: Explosively launched spores of ascomycete fungi have drag-minimizing shapes.

The drag experienced by these fungal spores is within one percent of the absolute minimum possible drag for their size. But these shapes are seen only among spores distributed by air flow, not those which are dispersed by animals.

An optimal drag-minimizing shape ensures that the spores can traverse several millimeters of still air surrounding the fungus' fruiting body; once past that point, the 10-micron spores are light enough to be propelled by even the gentlest breeze.

Also at the end of last year, in PLoS ONE, The Fastest Flights in Nature: High-Speed Spore Discharge Mechanisms among Fungi. Using ultra-high-speed video cameras the launch process in four species of fungi that grow on the dung of herbivores was documented. One of these species was the Pilobolus I mentioned in class. Launch speeds ranged from 2 to 25 m s⁻¹ and corresponding accelerations of 20,000 to 180,000 g propelled spores over distances of up to 2.5 meters.

Don't forget the Lotusland trip tomorrow. 1pm sharp by the Old Little Theater. Weather forecast for Saturday is currently cloudy with a 10% chance of precipitation although the afternoon looks like it should stay dry.

Pulsating mass of fungus

I think this post is worthy of repetition - particularly since I couldn't remember why the Department of Defense was funding the study.

The 'Humongous Fungus' project was actually an offshoot of a grant from the Department of Defense, which funded a project to study the possible biological effects of ELF (Extra Low Frequency) stations in the Upper Peninsula of Michigan. These ELF stations were built to communicate underground with ocean-going submarines in time of war.

They sampled for the fungus by 'baiting' with tongue depressors. The fungal mycelium quickly colonized the wood sticks. They were not looking for a large fungus, or even trying to measure the size of any fungus. The project was originally to look at how mitochondrial DNA was inherited in fungi in nature.

When news of the 'giant fungus' broke in the press CNN wanted someone to go out into the woods and wave from the fungus so they could get an aerial picture of the humongous fungus.

Even better, a Japanese businessman called and wanted to build a boardwalk around the humongous fungus and charge people to view the 'pulsating mass of fungus'.

There's a really nice article by Tom Volk, first published in Inoculum in 2002, a decade after the discovery of the fungus. You can read the article online here.

If you'd like to read more about Beatrix Potter, and the 'unnatural union between a captive algal damsel and a tyrant fungal master.' check out this earlier post.

Humongous Fungus

If you'd like to read a little more about the original humongous fungus there's a really interesting article by Tom Volk, first published in Inoculum in 2002, a decade after the discovery of the fungus. You can read the article online here. The fungus they discovered, an individual Armillaria bulbosa, aka the honey mushroom, was conservatively estimated to be at least 1500 years old and weigh around 100 tons - making it one of the largest and oldest living organisms.

I learned lots of fascinating trivia from this article:

The project was actually an offshoot of a grant from the Department of Defense, which funded a project to study the possible biological effects of ELF (Extra Low Frequency) stations in the Upper Peninsula of Michigan. These ELF stations were built to communicate underground with ocean-going submarines in time of war.

They sampled for the fungus by 'baiting' with tongue depressors. The fungal mycelium quickly colonized the wood sticks.

They were not looking for a large fungus, or even trying to measure the size of any fungus. The project was originally to look at how mitochondrial DNA was inherited in fungi in nature.

When news of the 'giant fungus' broke in the press CNN wanted someone to go out into the woods and wave from the fungus so they could get an aerial picture of the humongous fungus.

Even better, a Japanese businessman called and wanted to build a boardwalk around the humongous fungus and charge people to view the 'pulsating mass of fungus'.

Beatrix versus the Botanists

When I was a sophomore at college in England I spent a summer working at the Freshwater Biological Association in the English Lake District. The cottage I stayed in was in a tiny village called Far Sawrey. Just down the road is the village of Near Sawrey which contains a small 17th century farm house where Beatrix Potter spent most of her later years, and where she wrote and set her many Peter Rabbit books.

Having mentioned it in class I thought I'd see if I could find out whether Beatrix Potter was happy in her later life or whether she resented being excluded from the male dominated scientific community. Thanks to the wonders of the internet I found a highly relevant book and, even better, the relevant chapter is available online as a sample chapter.

Chapter 1 of Liaisons of Life, Beatrix versus the Botanists, by Tom Wakeford describes Beatrix Potter's encounters with the scientific establishment. Fascinating reading and a picture of science at the turn of the century. Beatrix Potter was facing an uphill battle, not just as a woman in science but also in proposing lichens as a symbiotic and mutualistic association. James Crombie, a prominent English naturalist said:

"A useful and invigorating parasitism —who ever before heard of such a thing?"

and he described the relationship as:

"an unnatural union between a captive algal damsel and a tyrant fungal master."

After her aborted scientific career and her successful career as a children's author Beatrix Potter went on to a third, and equally successful career as a sheep breeder and conservationist in the English Lake District.

Diamonds of the kitchen

Lots of newspapers, including the Santa Barbara New-Press, picked up an an AP story today about the decline in the truffle harvest in Europe. Suspicion seems to rest on climate change but the article has the usual array of interesting truffle facts.

Specially trained dogs sniff and dig them out, and are rewarded with doggy treats. Pigs — bigger, hungrier and harder to manage — have largely fallen out of favor.

Chytridiomycota

Until recently the Chytridiomycota were thought to be mostly detritivores, living on dead material, but at least one species is pathogenic. The species of Chytridiomycota, or Chytrid fungi, that is killing amphibians worldwide is Batrachochytrium dendrobatidis.

Work carried out at UC Berkeley and published in PNAS last year now suggests that the fungus may end up playing a bigger role in the frog's demise than previously thought because of the pathogen's ability to spread over long distances and possibly persist in the environment as a consequence of sexual reproduction. A study of the genetics of the fungus provided the first evidence of genetic recombination in B. dendrobatidis, which results in multiple, related genotypes and suggests that sexual reproduction is occurring - even though spores have not been discovered.

This work was carried out in the Briggs lab in Integrative Biology in association with the Taylor lab in Plant and Microbial Biology and is part of a larger project on chytridiomycosis (the disease caused by B. dendrobatidis) and the mountain yellow-legged frog led by Cheryl Briggs, UC Berkeley associate professor of integrative biology. Cherie has now moved to UCSB so there is an opportunity to get involved in this research if it interests you.