This week the New York Times featured a story about local worms—in fact, a whole farm of them in Sonoma. Why a farm? To reduce waste from dairy animals such as cows and turn it into something useful—like healthy soil. The red wiggler worm creates a “vermicompost,” as it’s called, that adds nutrients to soil and can reduce disease in the plants that find their roots covered in it.

Pretty nifty! But our vermicomposting friends sound pretty low-tech compared to the earthworms that can produce cadmium telluride quantum dots that highlight cancer cells. What the…?

New Scientist explains cadmium telluride quantum dots:

These quantum dots have been used to improve the efficiency of solar panels and build high-tech display screens. However, to be able to use them in the body—to track cancer cells, for example—intricate and expensive chemical processes are required that can reduce the dots’ luminescence.

Publishing in Nature Nanotechnology, a team of British scientists have found that by mixing the right chemicals—cadmium chloride and sodium tellurite—in soil and dropping earthworms in, the worms, in their normal processes, are able to produce the quantum dots. Carl Zimmer describes it in his blog at National Geographic:

The worm-fashioned quantum dots played nicely with living cells, the scientists found. They could use the dots to make cancer cells shine amidst a background of ordinary tissue.

Well done!

Now for something completely different… Well, still in the worm vein—except penis worms are really entirely separate beasts, living fossils that date back to the Cambrian period.

Despite being over 500 million years old, this phylum with the snicker-inducing (albeit apt) name still has a lot to teach scientists. Last fall, researchers argued that an entire branch on the tree of life may need to be redefined due to penis worms’ gene-expression data.

Then, last week, scientists publishing in PLoS One determined that the earliest penis worms consumed just about anything and everything. Fossils of Ottoia prolifica often are found with their gut contents preserved, and, in this case, providing evidence of an extremely varied diet. National Geographic has a detailed list and creepy video of Ottoia’s modern-day relatives. (Don’t view at the dinner table.)

As we worm our way into 2013, let’s not forget our invertebrate friends!

Ottoia image: Smokeybjb/Wikipedia

Enter Caenorhabditis elegans, or C. elegans, scientists’ favorite worm. C. elegans has traveled on many spaceflights, making it the perfect study for aging and space travel.

Lifespan and aging rates in animals are influenced by numerous environmental factors, such as temperature, oxygen, and food intake. The effect of microgravitational space environments on aging remains poorly understood, in part because scientists must disentangle it from many other influences.

To address the question of spacefaring worms’ longevity, Yoko Honda of the Tokyo Metropolitan Institute of Gerontology examined ISS-flown C. elegans and compared them to earth-bound worms.

During the International C. elegans Experimental First project, scientists incubated worms and flew them for two days to the ISS. The worms resided on-board for nine days, and then returned to Earth to be flash frozen in liquid nitrogen. Control animals underwent the same procedures at the same time on the ground.

First off, the team noted that spaceflight suppressed the formation of particular compounds that normally accumulate with increasing age.

Secondly, the team looked at how spaceflight affected specific genes’ expression (not whether the genes smiled or frowned, but how efficiently the genes transfered the information they encode into actual proteins). The space travel downregulated seven of the worms’ genes: these genes encode proteins linked to neuronal or endocrine signaling. Honda and his colleagues observed that the inactivation of each of these genes led to an extension of the worms’ lifespan on the ground. So when the scientists “turned off” the genes that slowed down in space, the worms lived longer.

Space travel leads to longevity? Well, perhaps in worms. Further research is required, but the present study suggests that space-flown worms age more slowly compared with the control group, and hints that spaceflight may extend worm lifespan. Can astronauts hope for similar results? Far too early to tell…

The research appears in the current edition of Scientific Reports.

Image: Bob Goldstein, UNC Chapel Hill, Wikipedia

Researchers from the University of Alberta found that billions of years before life evolved in the oceans, thin layers of microbial matter in shallow water produced enough oxygen to support tiny, mobile life forms.

Science News puts it eloquently:

Such clumps of oxygen-producing gunk could have supplied the first mobile animals with food to eat and air to breathe.

The researchers say worm-like creatures could have lived on the oxygen produced by photosynthetic microbial material, even though oxygen concentrations in the surrounding water were not high enough to support life. The research was conducted in shallow lagoons in Venezuela where the high salt content is comparable to oceans older than 500 million years.

The link between biomats and animals is demonstrated by the trace-fossil record, which are tracks left behind by the movements of the worm-like creatures. The trace-fossil records for these animals date to at least 555 million years ago when oxygen levels would have been a tenth of what they are now.

These findings suggest that the appearance of animals was not dependent on an oxygenated ocean. Rather, the earliest animals could have lived within photosynthetic biomats and derived life-sustaining oxygen from that source.

The researchers say their work opens the door to the search for life in early periods of Earth’s history when it was believed there was absolutely no oxygen and no chance of finding life.

Image: Stefan Lalonde

The squid are part of an experiment to see if, like some collegiate females on spring break, good bacteria “go wild” in the microgravity of space. Bobtail squid use bacteria called Vibrio fischeri to generate light. According to Discovery News:

That light helps the squid hunt for prey in dark waters. It also provides camouflage from any organisms trying to eat him, because the squid doesn’t cast a telltale shadow on the ocean floor as a result of the moon’s rays shining down into the water.

Previous shuttle experiments have shown what happens to harmful bacteria in space, but this will be the first experiment with beneficial bacteria.  Scientists are hoping that these results with squid will translate to beneficial bacteria with humans.

The NASA press kit reports that worms are part of the mission:

One NASA experiment known as Biology (Bio) will use, among other items, C. elegans worms, that are descendants of worms that survived the STS-107 space shuttle Columbia accident.

Haven’t these worms been through enough?!

Wired UK has a breakdown of other microbes joining STS134:

The microbes on-board Endeavour include the tardigrades (nicknamed Water Bears) which are large extremophiles that can withstand temperatures as biting as absolute zero, and as hot as 150 degrees Celsius. They’re joined by the Deinococcus radiodurans (which NASA dubbed “Conan the Bacterium“) which can survive upward of 15,000 Gy of radiation — 10 Gy is more than enough to kill an average human.

Haloarcula marismortui (Old Salty) loves salt, and lives in levels of high salinity that would kill other organisms. Pyrococcus furiosus (Fire Eater) is all about heat, and thrives in temperatures over 100 degrees Celsius. Cupriavidus metallidurans (which doesn’t have a nickname, unfortunately) plays a vital role in the formation of gold nuggets, thanks to its love of gold tetrachloride: a compound that is toxic to most other microorganisms.

Finally there’s Bacillus subtilis (The Average Joe), which is a model organism used in hundreds of biological experiments. It’s been into space many times before, so it’ll be a good comparison point for other studies.

You know, Dorothy only had lions and tigers and bears to face in Oz…

Image by Hans Hillewaert/Wikimedia

That’s not aliens speaking to humans, but rather scientists speaking to worms, Caenorhabditis elegans, to be exact.

Poor C. elegans. It’s often researchers’ favorite choice because of its optical transparency and its well-defined nervous system of exactly 302 neurons. This time two different groups are using optogenetics, a way to control cell function with light, to manipulate the worms locomotion and behavior.

A group of scientists from Harvard, the University of Pennsylvania and the University of Massachusetts Medical School have come up with CoLBeRT (Controlling Locomotion and Behavior in Real Time) that uses colored lasers to control the worm while it’s moving.

“This optical instrument allows us to commandeer the nervous system of swimming or crawling nematodes [worms] using pulses of blue and green light—no wires, no electrodes,” says Aravinthan Samuel, a professor of physics and affiliate of Harvard’s Center for Brain Science. “We can activate or inactivate individual neurons or muscle cells, essentially turning the worm into a virtual biorobot.”

“If you shine blue light at a particular neuron near the front end of the worm, it perceives that as being touched and will back away,” says co-author Andrew M. Leifer, a PhD student also in Harvard’s Department of Physics and Center for Brain Science. “Similarly, blue light shined at the tail end of the modified worm will prompt it to move forward.”

(A video is of this mind-control is available here.)

By stimulating neurons associated with the worm’s reproductive system, they were even able to rouse the animal into secreting an egg.

A team from the Georgia Institute of Technology found that by using LCD projectors, they could also manipulate the worms’ movements. Apparently, according to Science News there are benefits to both technologies. CoLBeRT works as the worm is moving, and the Georgia Tech system has more precise targeting.

Both studies are published in the recent edition of Nature Methods. A subscription is needed to read the articles (Harvard et al and Georgia Tech), but an entire feature on optogenetics is available for free.

Image: Leifer et. al. / Nature Methods