What is a (Volvox) species?

Hisayoshi Nozaki and colleagues have just described some Volvox samples from two lakes and a pond in Japan.

Figure 1A from Nozaki et al. 2016. Volvox sp. Sagami asexual spheroid with daughter colonies (d).

Figure 1A from Nozaki et al. 2016. Volvox sp. Sagami asexual spheroid with daughter colonies (d).

The newly collected strains have a lot in common with another recently described species, Volvox ferrisii, but there are some important differences as well:

…it could be clearly distinguished from all previously described monoecious species of Volvox sect. Volvox by its small number of eggs or zygotes (5–25) in sexual spheroids, with short acute spines (up to 3 μm long) on the zygote walls and elongated anterior somatic cells in asexual spheroids.

In spite of these differences, Nozaki and colleagues stop short of calling the newly collected strains a new species. Why?

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Volvox 2017 – save the date

The Fourth International Volvox Conference will be held in St. Louis, Missouri August 16-19, 2017, with Jim Umen organizing.

Starting in 2011, we have had a Volvox meeting every other year (every year there’s not a Chlamydomonas meeting, that is). The first meeting was at Biosphere 2 outside of Tucson, Arizona, the second at the University of New Brunswick, and the third at Cambridge University.

Biosphere 2

Biosphere 2, the site of the First International Volvox Meeting in 2011.

You don’t have to study Volvox to join us; the meeting is open to anyone with an interest in the evolution of multicellularity (last year’s invited speaker was Professor Pauline Schapp, who studies cellular slime molds).

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Volvox live wallpaper for Android

Anybody remember iGoogle? Kind of a customizable home page for your web browser. I used it until they shut it down, and I even spent a few hours designing a Volvox iGoogle theme (when I should have been writing my thesis):

igoogle

I think three or four people used it; Google would only tell me “less than 100.” Nevertheless, if you feel the need for some Volvox in your life but you don’t have a handy supply of AF-6 medium, lighted incubator, and dissecting scope, there’s still a way:

We have a good news for all VOLVOX fans. You can grow VOLVOX on your smartphone!

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Coenobium wine

Between the unpacking and the travel, I haven’t had much chance to explore Atlanta, but one of my favorite places so far is Krog Street Market, an indoor market with some really excellent food and beer. I was surprised while browsing Hop City to see this among the Italian wines:

Coenobium wine, purchased at Krog Street Market.

Coenobium wine, purchased at Krog Street Market.

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Volvox the art gallery

Volvox Art Gallery. Image from http://www.volvox-stnk.net/.Volvox Art Gallery. Image from www.volvox-stnk.net/.

If you’ve ever seen Volvox alive under a microscope, you probably remember it. They are beautiful, huge (relative to most things in a drop of pond water), and seemingly purposeful as they roll across the field of view. Volvox and its relatives have also played important roles in some big scientific and philosophical discussions, such as the evolution of multicellularity, the evolution of cooperation, and the nature of biological individuality. Given all that, it’s probably not too surprising that the volvocine algae, and Volvox in particular, have inspired a lot of art, including paintings,

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Retrogenes in Volvox and Chlamy

The evolution of multicellularity in the volvocine algae appears to have happened primarily through co-option of existing genes for new functions. For example, the initial transition from a unicellular life cycle to a simple multicellular one involved the retinoblastoma gene, as Hanschen and colleagues elegantly demonstrated (see “The evolution of undifferentiated multicellularity: the Gonium genome“). A Volvox gene involved in cellular differentiation, regA, was likely co-opted from an ancestral role in environmental sensing, and a similar origin appears to explain the use of cyclic AMP for the signaling that causes multicellular aggregation in cellular slime molds (see “Volvox 2015: evolution“). 

Some of the changes leading to complex multicellularity, though, clearly did involve new genes. Two gene families involved in building the extracellular matrix that makes up most of a Volvox colony, the pherophorins and metalloproteinases, have undergone multiple duplication events leading to greatly expanded gene families (see “Heads I win; tails you lose: Evolution News & Views on Gonium, part 2“). One mechanism by which genes are duplicated is retroposition, in which a messenger RNA is reverse transcribed into DNA and inserted into the genome:

Fig S1A from Jakalski et al. 2016. Basic mechanism of retroposition. DNA is transcribed into a pre-mRNA by RNA polymerase, introns are spliced out, and a poly(A) tail is added to the 3′ end, resulting in a mature messenger RNA. The mRNA is then reverse-transcribed to DNA and inserted into a new genomic location.

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Graduate student position in the Nedelcu lab

If you’re a fan of Volvox and the volvocine algae and have recently received an undergraduate degree in biology or a related field, now’s your chance to get serious about studying them. Aurora Nedelcu is looking for a graduate student to join her lab at the University of New Brunswick. Professor Nedelcu is a major player in the Volvox community, having published foundational papers on diverse aspects of volvocine biology and organized the first two international Volvox meetings. This is a great opportunity to join a vibrant and growing research community:

A graduate student position is available in the laboratory of Aurora Nedelcu, in the Department of Biology at the University of New Brunswick, Fredericton, CANADA. Research in our laboratory is directed towards understanding general, fundamental issues in evolution – such as the evolution of multicellularity, development, cell differentiation, sex, programmed cell death, altruism.  Our research is rooted in the framework of transitions in individuality and evolution of complexity (at a conceptual level), and of cellular responses to stress (at a more mechanistic level).  The experimental model-system we are currently using is the green algal group, Volvocales (see our Volvocales Information Project; http://www.unbf.ca/vip). Highly motivated students with interests in either theoretical/genomics or experimental/molecular approaches, and previous research experience are encouraged to apply. Interested applicants should e-mail a CV, summary of research experience and interests, unofficial transcripts, and contact information for three referees to [email protected].

Applicants should meet the minimum requirements for acceptance in the Biology Department Graduate Program (see http://www2.unb.ca/biology/Degree_Info/Graduate.html).

I’m going to Cyprus!

Phycomorph_logo3

I’m heading to Limassol, Cyprus at the end of September to talk about Volvox morphology and evolution. Phycomorph is a European group studying seaweed development and reproduction, with a large focus on cultivation. I have an extra day after the meeting, so hopefully I’ll get to explore a bit.

The organizers were initially worried about the high cost of transportation from Missoula, but I had good news for them: I won’t be flying from Missoula but from Atlanta, which is (seriously) half as expensive. The timing of the flights is a bit unfortunate, though, so I’ll have a couple of very long layovers in Heathrow (17 and 20 hours).

 

The preliminary list of confirmed speakers is:

Phycomorph speakers

 

The evolution of undifferentiated multicellularity: the Gonium genome

Blogging took a backseat to the wedding of two dear friends two weekends ago and to morel hunting last weekend, so I’m only now getting around to a post that should have been written weeks ago (I promised on April 22 that it would be out the following week). Last month, Erik Hanschen and colleagues published the Gonium pectorale genome, filling in some crucial bits of the transition to multicellular life in the volvocine algae. This was a big project, taking several years and involving over 20 authors from over a dozen institutions. The final paper is open access in Nature Communications.

I did post an effort to explain some aspects of the paper to the cdesign proponentsists at Evolution News and Views, who, by their own admission, failed to understand it (“After reading this paper, we’re none the wiser.”). I also complained of the science media’s tendency to refer to all algae as ‘pond scum.’ The lead author of the genome paper kindly followed up with a guest post addressing some of ENV‘s other misunderstandings, such as the purpose of model organisms in biology and the difference between ‘assertion’ and ‘evidence’. But now it’s time to dig into what the genome paper actually says.

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