Small Things Considered

Pictures Considered #32 : A Model for DNA Segregation in 1963

by Nanne Nanninga
The classic paper on 'The Regulation of DNA Replication in Bacteria' by Jacob et al. (1963) included a model on bacterial DNA segregation. In retrospect the model had far reaching consequences which can still be felt today. It entailed a research program that inspired many scientists. Yet, the model was not the main topic of the paper. Read more →

Your Operating System on a Thumbdrive – A Snippet

by Christoph
At the heart of every cell's 'operating system' you find the ribosomes, these ingenious nano‑machines that translate messenger RNA (mRNA) into all kinds of proteins the cell needs to build and maintain itself. Ribosomes were first described by the electron-microscopist George Palade in a paper from 1955, in which he ponders on... Read more →

A Rickettsia Takes a Walk (or Two)

by Monika Buczek
Take a walk through the woods this fall and you might find yourself being feasted upon by all sorts of little beasties, from the macro to the micro. Some of the most common tiny predators are ticks and fleas, found all over the world. Although a nuisance in themselves, these external parasites harbor even smaller microbial invaders, easily passed between humans and... Read more →

Talmudic Question #128

To turn the tables, are there eukaryotic endosymbionts of prokaryotes? (Keep in mind that some bacteria are larger than the smallest eukaryotes.) Read more →

Symbiont Exchange in the Aphid·Buchnera Symbiosis (2|2)

by Christoph
What's possible in the wild – symbiont exchange, see last week's part 1 – should also be possible to achieve in the lab. Less for competing with nature's ingenuity but more with the aim to study the separate contributions of symbiotic partners, of course. So, after being successful earlier in transferring secondary, facultative endosymbionts between aphid hosts, the Moran lab developed... Read more →

A Snippet: Who Invented Agriculture, the Ants or the Bees?

by Elio
Agriculture was invented at the time of the dinosaurs, long before there was anything resembling a primate on earth. Take the example of the leaf cutting ants. For about 50 million years, they have been harvesting plant material, bringing it to their nest, chewing it up, and using the chewate to grow fungi, which is what they eat... Read more →

Symbiont Exchange in the Aphid·Buchnera Symbiosis (1|2)

by Christoph
For evolutionary biologists, the aphid·Buchnera symbiosis is a favorite model to study 'or­ga­nel­lo­ge­ne­sis', how a once free-living gammaproteobacterium became an obligatory endosymbiont of its aphid host – now its buddy rather – over the course of >200 Ma (million years) of co-evolution. Todays... Read more →

Pictures Considered #31 : An Endosymbiont On Its Way To Becoming An Organelle?

by Elio
Inside, the freshwater ameba Paulinella chromatophora carries what may be a missing link in an endosymbiont becoming an organelle. We discussed this before in some detail. Paulinella carries within it one or two large sausage-shaped photosynthetic endosymbionts that look like cyanobacteria. This endosymbiont’s genome is a respectable... Read more →

Life in a Sea of Gradients

by Brandon P. Kieft
The resources available to marine microbes are patchy. Though seawater looks uniform and limpid to our eyes, that is far from the truth. Studying the oceans on a microscale has revealed that it is highly heterogeneous, having features such as marine snow and intricate chemical gradients. Therefore, microbial cells in the marine environment certainly do not all have a uniform experience. This is reflected in their... Read more →