Roland Thaxter’s 19th century drawings of myxobacteria

Scott Chimileski Animalcule - Roland Thaxter Myxobacteria

Roland Thaxter observed and sketched many social behaviors for myxobacterial species long before they were experimentally characterized. Bot. Gaz. 17(12):389-406 (1892). (Public Domain).

I now sit within a secluded nook of the Sterling Memorial Library at Yale University, working alongside my sister, Lindsay. I am writing my dissertation (or perhaps more accurately, writing a blog article), while my sister puts together quizzes for an herbal medicine class she teaches. I find the occasion ideal to highlight these remarkable drawings of myxobacterial social behaviors by Roland Thaxter, who collected some of his samples here in New Haven. I was recently led to Thaxter’s images indirectly while reading E.O. Wilson’s 1975 book, Sociobiology.

Scott Chimileski Animalcule - Thaxter myxobacteria

There is little doubt that in this image, Thaxter has drawn swarming myxo cells moving out from the periphery of the colony. This phenomenon is strikingly reminiscent of modern studies of predataxis behavior.

Thaxter published these drawings in the Botanical Gazette in 1892, in “On the Myxobacteriaceae, a New Order of Schizomycetes.” Though Schizomycetes is an archaic botanical term for bacteria, Thaxter’s classification was among the first to separate myxobacteria from fungi, the branch of life in which they had previously been grouped. The drawings shown in this post represent species from the genera Chondromyces, Stigmatella, Archangium and Myxococcus.

“A few years since while collecting fungi at Kittery and in several other localities in New England and the southern states, the writer’s attention was attracted by a bright orange-colored growth occurring upon decaying wood, fungi and similar substances, which, although in gross appearance it seemed somewhat highly organized, was found, when examined in a presumably mature condition, to consist of apparently amorphous material, without signs of hyphae or spores of any kind. Its general appearance and the character of the substance which composed it suggested an immature condition of some myxomycete which had become dried while in the act of rising from the substratum to form its fruitification.”                                                                                                                                                                                                                   – Roland Thaxter, 1892

G.P. Clinton wrote a biography of Roland Thaxter for the National Academy of Sciences in 1935.  Thaxter was born in New England and spent most of his life here (like me, so far at least). In addition to New Haven, he collected samples in Kittery Point, Maine, where he spent many summers, and in Cambridge, MA, where he worked as a professor at Harvard for the bulk of his career.

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As a botanist, Thaxter’s attention was drawn to structural detail. This could explain how he was able to single out and produce the first descriptions of some of the most developmentally complex bacterial groups to be discovered, even to this day. According to Clinton, he was very much of the “pure science” type—less interested in practical applications for botany. It seems the division between these two ways of approaching science was already palpable in 1933.

Clinton also suggests that Thaxter’s success as a scientist was linked with his artistic creativity. The fact that these sketches are relevant and inspirational to me, a microbiologist studying social behaviors over 100 years later, is another testament to Thaxter’s artwork.

Scott Chimileski- Thaxter - Sociomicrobiology Myxobacteria

E.O. Wilson highlighted these drawings of fruiting body development in his 1975 book, Sociobiology.

 

Writing  within the historic Sterling Memorial Library at Yale University!

Yale Sterling Library

Yale Sterling Library

While I was talking to an old man …

“While I was talking to an old man (who leads a sober life, and never drinks brandy or tobacco, and very seldom any wine) my eye fell upon his teeth, which were all coated over; so I asked him when he had last cleaned his mouth? And I got for an answer that he’d never washed his mouth in all his life … I took some of the matter that was lodged between and against his teeth, and mixing it with his own spit, and also with fair water (in which there were no animalcules), I found an unbelievably great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time.”
               – Antonie van Leeuwenhoek, Letter 39, September 17, 1683

The Tiny Giants exhibit from Bigelow Laboratory

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I had a chance to visit the Tiny Giants: Marine Microbes Revealed on a Grand Scale exhibit this week, at the Portland Public Library in Maine. Produced by scientists from the Bigelow Laboratory for Ocean Science, the exhibit features photomicrographs of phytoplankton and zooplankton, focused on diatoms and dinoflagellates. Images on display were collected through both light microscopy and electron microscopy.

If you are within driving distance of Portland, I highly recommend visiting the exhibit (on display until March 31).

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A variety of microscopic crustaceans and unicellular algae.

 

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“Predator in Pink.” A predatory dinoflagellate, Protoperidinium, with a natural pink tinge. Photo credit: Dr. Peter Countway

 

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Marine snails: Limacina helicina. Photo credit: Laura Lubelczyk

 

More information about the exhibit:

http://www.pressherald.com/2015/03/08/microbes-loom-large-at-portland-library/

 

A fantastic sunset on an early spring night in Portland, Maine.

A fantastic sunset on an early spring night in Portland, Maine.

The first @ASM meeting on sociomicrobiology

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This weekend I was fortunate to be one of fifty microbiologists at the first @ASM meeting: a new conference format held at the headquarters of the American Society of Microbiology in Washington, D.C. Not only was this the first @ASM meeting – it was also the first ASM Conference on Mechanisms of Interbacterial Cooperation and Competition, or effectively (as noted by many of the participants): sociomicrobiology.

ASM headquarters: located in a beautiful brick building in Washington, D.C.

ASM headquarters: located in a beautiful brick building in Washington, D.C.

Each and every talk was truly excellent, but of course I did have some favorites, biased no doubt by my own interests:

  • Both Peter Greenberg and Kevin Foster presented a broad context for the concept of sociomicrobiology, as it is developing into a new science. Peter Greenberg framed his talk around quorum sensing, while Kevin Foster is doing some amazing work from the perspective of the evolution of social behaviors and particularity in the application of computational modeling of biofilm formation. In many ways microbes are ideal organisms for empirically testing the first principles of social interactions.
  • Susanne Mueller, a research scientist from the Kirby Lab at the University of Iowa, gave a fascinating talk based on two recent papers on Myxococcus/Bacillus interactions. B. subtilis forms a newly discovered form of biofilm called the megastructure only in response to Myxo predation. Megastructures are filled with spores and are not dependent on the same genes involved in colony biofilm formation, suggesting a unique mixture of unknown matrix components.
  • Elizabeth Shank presented work from her group at the University of North Carolina, advancing previous studies visualizing matrix expression and unique functional cell types in B. subtilis biofilms. She has shown that matrix expression in B. subtilis can be triggered by other sympatric species: induced by particular metabolites (for example, Thiocillin).
  • Paul Straight’s talk on chemical interfaces between Streptomyces and B. subtilis colony biofilms included some great photographs. His work shows that two colony biofilms grown adjacent to each other are engaged in a complex exchange of chemical information.
  • There were also many talks on type VI secretion systems (T6SS; by and large the major theme of the conference): a mechanism for effector secretion that is structurally homologous to bacteriophage components. These began with a great keynote talk by John Mekalanos, whose group discovered T6SS in 2006. It was amazing to see how such a transformative discovery can open up an entire field in less than a decade.
  • Harry Mobley discussed the history of swarming in Proteus mirabilis, in what was a very informative but also very entertaining talk (I think he gets the award for most laughter). He focused on the formation of Dienes lines between successive layers of swarming cells in this species, and how these characteristic boundary layers are now known to be mediated by T6SS.

Based on the success of this meeting, plans for the next ASM sociomicrobiology meeting are already underway.  It remains to be determined whether the conference will be expanded in size, or left at the extremely small 50 person level. I can say that 50 people was very nice; I met essentially everyone, and the poster session was excellent: incomparable to the field of posters at the general meeting.

A quick run past the white house on a cloudy day!

A quick run past the white house on a cloudy day!