Small Things Considered

Fine Literature: Bacterial Shape---Not a Small Thing

From time to time, I will list review articles that I found inspiring and enlightening. To start with, I greatly enjoyed the following:

Kevin D. Young. 2006. The Selective Value of Bacterial Shape. Microbiology and Molecular Biology Reviews 70 (3): 660-703.
http://mmbr.asm.org/cgi/content/full/70/3/660

To quote from the first paragraph:

To be brutally honest, few people care that bacteria have different shapes. Which is a shame, because the bacteria seem to care very much. A simple way to verify this is to take a leisurely stroll through Bergey's Manual of Determinative Bacteriology or The Prokaryotes, pausing to admire the surprising and bewildering riot of shapes, sizes, and aggregates, some of which are illustrated in Fig. 1.

Figure 1. For the legend, refer to the paper.

Talmudic Question #16

Invertebrates are said to have only innate immunity. Why do you suppose they have not evolved acquired immunity, as vertebrates have done?

A "Compte Rendu"

Some distinguished French journals, both old and contemporary, are called Comptes rendus..., a term that to me has the right sound for this entry. Loosely translated it means "accounts rendered."

I wish to render an account of this blog's first six month of existence.

Structural Grace

Francis Crick made several pencil drawings of his concept of the structure of DNA. This one (1953) seems particularly graceful.

Drawing ©The Wellcome Library
London

Two-For-the-Price–of-One Symbiosis

   
Bread mold, another
Rhizopus. Source:
Skidmore College,
Plant Biology.

We are used to titillating stories of symbiotic mutualism where the host and the symbiont do amazing things together that neither could do alone. Think of lichens, root nodules in legumes, tube worms in deep sea vents. Such phenomena make us wonder: are there any limits to the evolution of novel adaptive strategies?

Here is an especially exciting example—a symbiont that does not just one unexpected thing with its host but two.

The two partners are a fungus, Rhizopus microsporus, and a bacterium belonging to the genus Burkholderia.

Talmudic Question #15

Why are only prokaryotes known to carry out biological nitrogen fixation?

It Takes Three to Tango

by Merry

A handsome member of the sharpshooter
family. Photo from Sayer's photo gallery
of interesting  insects

Glassy-winged sharpshooters, long notorious in wine country as an insect vector for Pierce's disease in grapes, have recently achieved notice for employing not one but two bacterial endosymbionts to provide essential nutrients.  One provides amino acids while the other supplies cofactors, especially water-soluble B-family vitamins.

Talmudic Question # 14

Why are so many more phyla of Gram negative bacteria than of Gram positives (at least in the more conventionally used  phylogenetic schemes)?

Mushrooms And Global Warming

Global warming may have a silver lining, at least for those who enjoy wild mushrooms (e.g., the writer of this blog).

Speak or Swim—But Not Both

Many pathogenic bacteria “speak” a chemical language by inserting proteins into host cells that affect the microbe’s ability to invade or damage the host.  For the insertion, they use a complex needle made up of a number of proteins (called a Type III secretion system). Similar proteins in similar structural arrangements are also involved in making the basal body of the flagella used for swimming. The two pieces of machinery, though differing in function, are evolutionarily related. Not only that, they interact with one another.