(Roughly) Daily

“There are more things in heaven and Earth, Horatio, than are dreamt of in your philosophy”*…

And some of them were recently found in the woods near Boston…

Researchers have unearthed a trove of wonders in the soil of a Massachusetts forest: an assortment of giant viruses unlike anything scientists had ever seen. The find suggests this group of relatively massive parasites has an even greater ecological diversity and evolutionary importance than researchers knew.

Giant viruses can exceed 2 micrometers in diameter, on par with some bacteria. They can also harbor immense genomes, which reach 2.5 megabases—larger than the genomes of far more complex organisms. Between the discovery of these impressively sized viruses in algae and the culturing of amoeba-infecting Mimiviruses, most of the research on the group has focused on viruses that inhabit freshwater environments. But DNA sequencing has long indicated that giant viruses are diverse and abundant elsewhere, too—especially in sediments and soils, which are estimated to host some 97% of all the viral particles on Earth. Indeed, genomic sequencing of the soils of Harvard Forest—a roughly 16-square-kilometer area west of Boston—indicated the presence of numerous, novel giant viruses.

Now, electron microscopy has allowed scientists to see what others had only sequenced. The diversity of forms was astounding, they report in a bioRxiv preprint. Not only did the researchers see the 20-sided icosahedral shapes they expected, they spotted ones with myriad modifications—tails, altered points, and multilayered or channeled structures abounded. There were even viruses with long tubular appendages, which the team dubbed “Gorgon” morphology [photo above]. Furthermore, many of these putative viral particles were coated with almost hairlike projections, which varied in length, thickness, density, and shape.

The findings suggest virologists have much to discover about how giant viruses interact with their host cells. That likely means the ecological roles these viruses play in soils—and elsewhere they’re found—are woefully underappreciated…

Microbes come in a variety of shapes, hinting at undiscovered ecological diversity: “Alien-looking viruses discovered in Massachusetts forest,” in @ScienceMagazine.

* Shakespeare, Hamlet

As we marvel at multifariousness (and note that viruses, while generally considered to be non-living and thus not considered microorganisms, are colloquially lumped in with microbes), we might spare a thought for Sidney Walter Fox; he died on this date in 1998.  A biochemist, he was responsible for a series of discoveries about the origin of life.  Fox believed in the process of abiogenesis, by which life spontaneously organized itself from the colloquially known “primordial soup,” poolings of various simple organic molecules that existed during the time before life on Earth.  In his experiments (which possessed, he believed, conditions like those of primordial Earth), he demonstrated that it is possible to create protein-like structures from inorganic molecules and thermal energy.  Dr. Fox went on to create microspheres that he said closely resembled bacterial cells and concluded that they could be similar to the earliest forms of life or protocells.


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