by Davide Ciccarese
Bacterial communities live in a small world where cells fill any available micron. Depending on their location and surrounding environment, they can readily respond to changes by gearing up their gene repertoire to insure their position in a densely packed biofilm. To be able to visualize this...
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Go FISHing to Image Bacterial Communities
Pictures Considered #61: how FtsZ-rings get shoveled to midcell in vitro
by Christoph
The last thirty years have been an "eye-opening" journey for microbial cell biologists, quite literally. I am, of course, talking about fluorescent labeling of individual cell components and the non‑invasive observation of their "behavior" in living bacterial cells. Just recently, I considered a video clip about Vibrio cholerae harpooning DNA. Now again a video clip, about...
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Pictures Considered #60: Vibrio cholerae harpooning DNA
by Christoph
Let me start with an adage: a picture is worth a thousand words. Can this also be valid for video snippets? I think so. Here you see a few seconds of a looping video showing how a cholera bacterium extends a pilus, attaches the tip to DNA in the environment, and then retracts it. Worth a thousand words? Yes, sure, but also deserving 1,000 words...
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Pictures Considered #58: Visualizing Introns
When we talk about genes and genomes today, we almost reflexively thinks of long strings of the letters G, A, T, and C. And by reading sequences, we easily detect stretches that code for proteins. We detect promoters, transcription factor binding motifs, start/stop signals for transcription, signals where introns are removed by splicing from primary transcripts... Read more →
Of Terms in Biology: DGGE
DGGE, to keep the title short, stands for denaturing gradient gel electrophoresis. You may wonder what an electrophoresis technique is doing in our 'of Terms in Biology' section, but it was once a nifty way to explore microbial diversity in environmental samples. And sometimes it still is, which struck me... Read more →
Heavy-duty Traffic, Microscale
by Christoph
Mention "flagella" and we microbiologists instantly think of these ingenious appendages that bacterial cells use to propel themselves through fluids of varying viscosities (archaea do this, too, with their archaella). We rarely think of them as an accessory to transport cargo. Yes "cargo," you read correctly, but maybe you remember...
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Of Terms in Biology: The Polony Method
by Christoph
If there is one venerable laboratory technique in virology, it is the plaque assay for the detection and quantification of bacteriophages. It was pioneered by Felix d'Herelle already around 1917, and in the early 1950s, plaque assays were also established for eukaryotic viruses...
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Grant's Anatomy
by Christoph
At an EMBO workshop in Copenhagen in 2006 on 'Cell cycle and cytoskeletal elements in bacteria,' I was almost unable to stay put in my seat during one presentation: Grant Jensen showed the 3D-montage of cryoET images of magnetosomes in Magnetospirillum magnetotacticum. It was a visual journey into and through the interior of a cell,...
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Getting to grips with the intangible
by Christoph
Imagine the E. coli nucleoid as a swig but of of a highly viscous tangle of a 2 nm thin and ~1.5 mm long DNA polymer, decorated with and highly compacted by a plethora of proteins, and somehow suspended in the cytoplasm of a cell with a volume of ~1.3 µm3. It's virtually impossible to "grip" the nucleoid, to measure...
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Of Terms in Biology: Phylogeny, Phylogenetics, Phylogenomics
by Elio
You may remember the solemn proclamation that "ontogeny recapitulates phylogeny," meaning that during our embryological development we (and everybody else) go through the steps in our evolution. This turns out to be quite wrong, but I bring it up because because it illustrates that phylogeny denotes the history...
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