Small Things Considered

Let's make some more tyrosine, together! (part 1)

by Christoph | Surprisingly, it is not particu­lar­ly dif­fi­cult to per­suade the yeast S. ce­re­vi­si­ae to ac­cept E. co­li bac­te­ria as 'room­mates', that is, as sub­sti­tu­te for de­fec­ti­ve mi­to­chon­dria (see Elio's recent blog). As 'hous­ing me­di­a­tor' you have to pro­vide the pro­spec­ti­ve room­mate with a de­fense against the host's SNARE sys­tem, 'dis­able' both part­ners by en­gin­eering... Read more →

Sensing Quorum Backwards

by Elio | Obvious in the establishment and progress in bacterial patho­genesis is that the inoculum, the number of bacteria entering their host at one time, must be of an effective size. Depending on the infectivity of the species, this can vary from a single bacterium to millions of them. Read more →

Go Ahead, Prove that Eukaryotic Cells AroseVia Endosymbiosis

by Elio | Say you want to prove once and for all the endosymbiotic theory of the origin of eukaryotic cells, substantiating that a cell (according to many, an archaeon) acquired a bacterium that eventually morphed into a mitochondrion. Read more →

Symbiosis

by Elio et al. | For as long as I can re­mem­ber, I have been fas­ci­na­ted by the sub­ject of sym­bio­sis. This is one of the grand themes in bio­lo­gy, what Mar­ga­ret McFall-Ngai has apt­ly called 'the ele­phant in the room', de­serv­ing much love and at­tent­ion. But ex­act­ly, what is it that is so fas­ci­na­ting about it? Read more →

Snacking on thistles (second bite)

by Christoph | For the thistle tortoise beet­le, Cas­si­da ru­bi­gi­no­sa, bit­ing once into its pre­fer­red food is not enough, it tak­es a se­cond bite. So, 80 years af­ter the first de­scrip­tion of a bac­te­ri­al sym­biont in C. ru­bi­gi­no­sa by H.-J. Stam­mer, Hassan Salem and his col­lea­gues took up the thread and stu­di­ed the sym­biont to more... Read more →

Snacking on thistles (first bite)

by Christoph | Way back in 1936, the zoologist H.-J. Stammer published a study of various beetles of the Cassidinae family (order Co­le­o­ptera) and their microbial symbionts. Among them was the thistle tortoise beetle, Cas­sida rubiginosa, an obligate foliovore, or put another way, a dedicated ve­gan with a penchant for thistles (Cirsium sp.). Thistles were a pest for far­mers in the pre-Roundup™ age, and some... Read more →

What To Do When You Run Out of a Cherished Symbiont?

by Elio | The answer is easy: pick up another one. This happens with the cicadas, those noisy insects that have been in the mindfulness of humans since antiquity. Cicadas, like aphids, psyllids, leafhoppers and others, feed on plant sap fluids, which are rich in sugars but poor in amino acids and vitamins. Read more →

Friend & Foe

by Christoph | In a post two month ago, I referred to 'defensive symbioses'. In a nutshell: one or more symbiotic bacteria produce a cocktail of antibiotics that provide protection of a eukaryotic host against an array of opportunistic bacterial and fungal pathogens. I introduced the term not in contrast but... Read more →

Even More Antibiotics In The Nursery!

by Christoph | We had learned earlier that Philanthus triangulum  beewolves – solitary digger wasps that prey on bees, hence their name – employ a "cocktail" of nine different antibiotics to protect their offspring from detrimental fungal infections. The antibiotics are produced – I repeat from the earlier post – by a bacterial symbiont, 'Candidatus Streptomyces philanthi', which the... Read more →

Fungomania II. The Humongousest Fungus

by Elio | We dealt with a monster fossil fungus before. In the interest of expediency, let me reprint part of what I said: "Several museums pos­sess specimens of a cylindrical organism named Prototaxites  whose tree-like trunks measure up to 8 meters long by 1 meter wide. Protota­xites  dated from approximately 420 to 350 million... Read more →