Small Things Considered

Fungi, Toxins, and Fungal Viruses (A Snippet)

by Elio | Fungi make toxins (called, not surprisingly, mycotoxins). This won’t surprise you because you know that certain mushrooms are poisonous and you may know of the aflatoxins, noxious chemicals made by molds that grow on stored grains. Read more →

Phage Phactories

by Merry | it’s not news to STC readers that phages encode cytoskeletal proteins. Daniel Haeusser’s fine post related this story as it was known in 2012. Two key papers published that year investigated the tubulin homologs found in phage genomes. At that time, phage-encoded tubu­lin homologs fell into two phylogenetic clusters... Read more →

"We Are What We Are"

by Christoph Weigel | If I were a stage director and contracted for another revival of the Broadway show 'La Cage aux Folles' (including the chorus line's "We Are What We Are" ) I would not waver a minute to choose for all leading roles members of the Pseudomonas family. All are true professionals (method acting, Meisner technique ), versatile in acting solo, or as a team, in dancing and in singing. Read more →

Old Enzymes Tell Stories

by Elio | Offhand, what can you say about the enzymes of the earliest cells? Surely, a few things pop up, for example, they were fewer in number and probably simpler than the ones we have now. They must have had fewer frills than the modern ones, which tend to have clear-cut tastes for substrates and... Read more →

tRNA Chop Shop: Retrotransposons Beware

by Jamie Henzy | Vertebrate genomes are teeming with sequences from retroviruses that have infected the cells of the germ line over the course of evolution. Known as endogenous retroviruses (ERVs), the vast majority of these once fierce foes have been defanged by mutations that make them incapable of expressing viral proteins, let alone infectious particles. Read more →

When it comes to HERV-K, I beg to differ

by Jamie Henzy | Although it's a regular occurrence for bacteria to acquire new genes whole cloth, by horizontal gene transfer, such events are rather rare for complex eukaryotes like us. Eukaryotes are vastly more inclined to take advantage of gene duplication events. An exception to this rule is the presence in vertebrate genomes of numerous retroviral sequences (endogenous retroviruses, or ERVs, for short) that were acquired presumably when a retrovirus infected a sperm or egg cell. Read more →

A naturalist's book of viruses

by Jamie Henzy | Who isn't intrigued by viruses? Capable of wiping out entire populations, causing epidemics of biblical proportions, and wrecking crops, viruses entered the consciousness of humans because of their destructive potential. Too tiny to be seen, they were born from Koch's postulates, at first existing only in the imaginations of their early discoverers, such as Beijerinck, Ivanovsky, Twort, and d'Herelle. In the 1940s, electron micrographs revealed the first shadowy images of bacteriophage particles, and the eeriness of their outlines encouraged dread and captured the imagination of those who saw them. Read more →

Prions in bacteria

by Vincent Racaniello | Bacteria do not develop transmissible spongi­form encephalopathies, but they have been found to produce prions – proteins that can adopt alternative conformations with different functions... Read more →

Quorum Sensing for the Mutes

by Christoph Weigel | It is (almost boringly) obvious that cell-to-cell com­mu­ni­ca­tion is vital in multicellular organisms. To function properly, all cells in a tissue have to know – and let their neighbors know – where exactly they are, which tasks they're performing right now, when it's time to differentiate, to propagate, and also when it's time to die. But when it comes to communication skills, ... Read more →

Cyanophages: Maximizing the Photo– and Redirecting the –Synthesis

by Daniel P. Haeusser | Happy Monday, readers! I hope you studied hard this weekend. Please put away your notes and close any open programs or browser tabs other than this one. It’s time for a Small Things Considered general biology quiz: In which of the following would you find genes for proteins involved in photosynthesis? (Note: One answer only!) Read more →