Volvox: a colony of cells

In 1950, a young assistant professor at Princeton University published an essay about Volvox in Scientific American, “Volvox: a colony of cells.” The essay touches on several themes that will be familiar to regular readers of Fierce Roller, including cellular differentiation, inversion, and what it means to be an individual.

The author was John Tyler Bonner, whose (much) more recent work I’ve written about previously (“Chance favors the minute animalcule: John Tyler Bonner on randomness“).

John Tyler Bonner

John Tyler Bonner, ca. 1957. Image from the Guggenheim Foundation.

Among many other contributions, Bonner was a pioneer in the development of the social amoeba (or cellular slime mold) Dictyostelium discoideum as a model system for multicellular development and cell-cell signaling. A member of the National Academy of Sciences and a fellow of the American Association for the Advancement of Science, he has published over twenty books and mountains of peer-reviewed papers.

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A quiet backwater

David Kirk‘s book is an essential resource for anyone who wants to study Volvox, even twenty years after its publication. It includes thorough but succinct reviews of volvocine diversity, ecology, genetics, development, and cell biology, along with original insights into all of these topics.

Volvox book cover

I was just returning to it for the many-th time to find a reference for a manuscript revision, and I (re-)discovered that a quote I’ve paraphrased many times comes from the Preface:

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Reminder: last day to enter the Volvox wall art giveaway

Today is the last day to enter the drawing for a ready-to-hang print of Volvox aureus on canvas. There’s no catch; all you have to do is go to and leave a comment with your favorite species (of anything). That’s it!

Right now there are only a dozen entries, so your odds of winning are pretty good. The winner will be announced on Monday.

Volvox aureus

Volvox aureus by me

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Undergraduate summer internships at the Danforth Center

This is an unbelievable opportunity: an NSF-funded, paid summer internship at the Donald Danforth Plant Science Center in St. Louis. Ru Zhang is at the Danforth Center. Jim Umen is at the Danforth Center. The Fourth International Volvox Conference was at the Danforth Center. If you’re an undergraduate and you think you might want to study Volvox or Chlamydomonas (or plants), this would be a great way to get started.

Danforth Internship

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Volvox wall art giveaway!

I had eight prints made (on canvas) of a micrograph I took in grad school of Volvox aureus. They turned out much better than I expected…it’s really hard to know how the color balance of something you’re looking at on a computer screen will look when it’s printed out. I’m going to give one away by random drawing. All you have to do to enter is leave a comment identifying your favorite species (of anything; rules below).

Volvox aureus

Volvox aureus by me

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Volvox newsletter

Volvox newsletter cover

As David Kirk pointed out, what we normally call the First through Fourth International Volvox Meetings are really about the fifth through eighth, as they were preceded by several meetings in the ’70s. The very first meeting was hosted by David and Marilyn Kirk at Washington University in St. Louis. Richard Starr, then at Indiana University, reported on the meeting in the first Volvox Newsletter (Dr. Starr would later move to the University of Texas, and his strains would form the beginning of the UTEX Culture Collection, which is still in operation).

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More Volvox correspondence

I previously corresponded with a science teacher in India, who wrote me with some questions about Volvox. After our initial exchange, my correspondent wrote

Can you please name if there is any unicellular colonial microorganism found?

I asked for clarification and received this reply:

I read about colonial organisms being unicellular and multicellular. Few people think Volvox as colonial organism which is unicellular while Phylum Bryozoa has colonial organisms which are multicellular. The confusion started here. What are colonial microorganisms really? If they are unicellular and multicellular why are they called as colonial then? Bacteria being unicellular which form colonies thought Can bacteria be called as colonial organism? I tried to look for the same but I have not found something solid which says bacteria can be called as colonial organisms. I want to explain colonial organisms to children and don’t want to provide wrong information.

Can you please help in understanding do colonial unicellular microorganism exist? I asked one of the microbiologist I know in here she is also not clear with the concept or probably I might have read something wrong. Need guidance.

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Mary Agard Pocock

Alexey Desnitskiy, Stuart Sym, and Pierre Durand have published a new paper in Transactions of the Royal Society of South Africa recounting the contributions of South African phycologist Mary Agard Pocock to Volvox research [full disclosure: Pierre Durand and I were labmates in Rick Michod’s lab at the University of Arizona for a time, and Alexey Desnitskiy is a friend and collaborator].

Pocock, who defended her Ph.D. in 1932, made careful observations of both sexual and asexual development in several species of Volvox that she collected in southern Africa: V. africanus, V. capensis,V. rousseletii, and V. gigas (which she originally described). For some of these species, hers are still the only detailed descriptions of their ontogeny:

Pocock studied almost all aspects of asexual and sexual development in several African Volvox species, with the exception of sexual differentiation control…Pocock’s data on embryonic inversion in V. africanus, V. capensis, V. gigas and V. rousseletii retain their importance today. Her description of inversion during asexual development in V. africanus and V. capensis remains the only detailed study of this process in these two species and her observations of embryonic inversion in V. gigas and V. rousseletii were corroborated almost 40 years later. [references omitted]

Pocock 1933 Fig. 2L-O

Figure 2L-O from Pocock 1933. Inversion in Volvox gigas.

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