An Ode to Unicellularity

Biosphere 2

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

This year’s Volvox meeting, as with the previous two, will feature an image/video/arts competition. Erik Hanschen, a graduate student in the Michod lab, has kindly granted me permission to post the winning entry in the poetry contest at the first Volvox meeting: a sonnet in honor of Chlamydomonas.

An Ode to Unicellularity – Erik Hanschen

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Actin evolution in the Volvocales

Kato-Minoura Figure 1

Fig. 1 from Kato-Minoura et al. 2015: Genomic structure of volvocine actin and NAP genes. For comparison, previously identified sequences are also shown. Filled boxes, putative coding exons; open boxes, putative 5′ and 3′ untranslated regions. Intervening sequences are shown by solid lines. Intron positions are indicated by codon and phase numbers with reference to the three alpha-actins of vertebrates (377 amino acids) (Weber and Kabsch 1994). The conserved intron positions are linked with dotted lines. ATG, translation start codon; TAA or TGA, stop codon.

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New Scientist article on experimental evolution of multicellularity

On the second day of AbSciCon, members of the Ratcliff lab and I met with a reporter, Bob Holmes, from New Scientist. We had all given our talks on the first day of the meeting. The resulting article came out yesterday.

I’ve dealt with New Scientist before, and I find them among the better science news outlets. They make a real effort to understand the science behind their stories, a refreshing change from sites that slap misleading headlines onto barely reworded university press releases. Aaaand I’m going to wrap this up before it turns into a rant.

Peter Conlin, Jennifer Pentz, Bob Holmes, and Will Ratcliff

Peter Conlin, Jennifer Pentz, Bob Holmes, and Will Ratcliff enjoying some sushi in a Chicago park.

Chlamy song

Posts may be thin this week. I am preparing a talk for AbSciCon and a manuscript that’s due Monday. Saturday morning, I will board the Empire Builder in Whitefish for a 30-hour ride to Chicago (no doubt some of the manuscript will be written on the train).

Meanwhile, here’s a song about Chlamydomonas (skip to 1:05 if you don’t want to hear the intro).

Expression and form: Arash Kianianmomeni on gene regulation

Kianianmomeni Figure 1

Figure 1 from Kianianmomeni 2015. Gene regulatory mechanisms behind the evolution of multicellularity. Model illustrating the role of gene regulatory mechanisms in the evolution of multicellular Volvox from a Chlamydomonas-like ancestor.

Arash Kianianmomeni’s latest paper in Communicative & Integrative Biology addresses the possible roles of gene regulation and alternative splicing in the evolution of multicellularity and cellular differentiation (Kianianmomeni, A. 2015. Potential impact of gene regulatory mechanisms on the evolution of multicellularity in the volvocine algae. Commun. Integr. Biol., 37–41. doi 10.1080/19420889.2015.1017175). The article is an ‘Addendum’ to a 2014 study by Kianianmomeni and colleagues in BMC Genomics. Communicative & Integrative Biology often invites authors to write these addenda after they have published a (usually high impact) paper elsewhere, providing authors the opportunity to publish material that was not included in the original paper due to space limitations or because it was opinionated or speculative. I may address the BMC Genomics article in a future post, but right now there is more new volvocine research than I have time to write about (it should be an exciting Volvox meeting this summer!).

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Congratulations to Maggie Boyd!

2015 UMCUR award winners with UM President Royce Engstrom.

2015 UMCUR award winners with UM President Royce Engstrom.

Undergraduate Maggie Boyd has been awarded the Life Sciences Poster Award in the University of Montana Conference for Undergraduate Research for her poster “Motility in Chlamydomonas reinhardtii.” This is kind of a big deal: only one poster award and one oral presentation award were bestowed in Life Sciences university-wide.

Maggie has also recently been awarded a Honerkamp-Smith Travel Grant to attend the Third International Volvox Meeting in Cambridge, U.K. this summer.

Ann Gauger teaches us about Volvox, part 2

Last time, I criticized Ann Gauger’s Evolution News and Views article “A Simple Transition to Multicellularity — Not!” for asserting that the requirement for kinesins in Volvox inversion implied a requirement for novel genes in the evolution of multicellularity. In a similar vein, Dr. Gauger presents programmed cell death and sex as problems for this transition:
The somatic cells commit suicide by a process known as apoptosis — programmed cell death — that I wrote about here. This process involves a minimum of several novel genes as well.
Where does this assertion that programmed cell death in Volvox “involves a minimum of several novel genes” come from? Programmed cell death (PCD) occurs in many unicellular eukaryotes, including Chlamydomonas reinhardtii. Furthermore, two types of metacaspases, genes involved in PCD in many algae and plants, are found in both Chlamydomonas and Volvox.
Metacaspases

Partial alignment of representative type I and type II metacaspase predicted sequences from red algae (Porphyra yezoensis; Py), green algae (Chlamydomonas reinhardtii, Cr; Volvox carteri, Vc), vascular plants (Arabidopsis thaliana; At), excavates (Trypanosoma cruzi, Tc; Leishmania braziliensis, Lb), diatoms (Thalassiosira pseudonana, Tp; Phaeodactylum tricornutum, Pt), haptophytes (Emiliania huxleyi; Eh), pelagophytes (Auroecoccus anaphagefferens; Aa), yeasts (Schizosaccharomyces pombe, Sp; Saccharomyces cerevisiae, Sc) showing the conservation of the cysteine-histidine dyad and the insertion characteristic of plant type II metacaspases. From Nedelcu, A.M. 2009. Comparative genomics of phylogenetically diverse unicellular eukaryotes provide new insights into the genetic basis for the evolution of the programmed cell death machinery. J. Mol. Evol., 68: 256–268. doi 10.1007/s00239-009-9201-1.

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