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Posts Tagged ‘biology’

A new shrimp farming technology devised by researchers in Texas is churning out record-setting levels of shrimp. Called super-intensive stacked raceways, its a system of indoor aquaculture that generates far more shrimp per cubic meter of water than open pond farming or any other aquaculture technique. And it could be deployed just about anywhere.

The shrimp grow in huge enclosed tubs called raceways, stacked four high in a column. As the shrimp develop and grow under computer-controlled conditions (the water is carefully circulated but not completely renewed, keeping environmental costs and water usage in check), they are moved downward from one raceway to the next--baby shrimp go in the top and progress downward to the bottom raceway, from which they are eventually harvested.

That innovation--the ability to raise very large, protein-rich shrimp (they’re called U15, but you probably know them as “jumbo”) in very little water--means the kilo-per-cubic-meter numbers are through-the-roof: 25 kilograms of shrimp from just one cubic meter of water. For some perspective, that’s equivalent to 1 million pounds of shrimp per acre of water. U.S. shrimp farms top out at about 20,000 pounds per acre of water. The best shrimp farms in tropical climates, working year round, yield something like 60,000 pounds per acre in a good year.

So we’re talking about a vast improvement to our shrimp stores. But the impact isn’t just an abundance of jumbo shrimp to batter up and fry. For one, it provides countries like the U.S. with a means to produce fresh shrimp (we import the vast majority of ours, and it’s usually frozen and thawed a few times before it gets to us). And shrimp exporters like China are on the verge of becoming shrimp importers due to socioeconomic trends and population growth, and that would make shrimp quite expensive. With stacked raceways, we could have our own domestic supply of shrimp, circumventing the need for a series of violent “shrimp wars.”

But further, this method could provide a simple-to-produce means of protein in places where food in general and protein in particular are growing scarce. Plus: jumbo shrimp you guys! These will go great on an hors d'oeuvre table next to those popper-optimized jalapenos we’ve been cultivating.

That’s not to say this is the first time a secret or hidden message has been encoded into a living molecule. But the method is quite simple, requiring no gene sequencing equipment, microscopes, or other scarce and expensive laboratory gear to extract the coded message. Some simple LEDs and a smartphone would suffice, allowing the recipient to receive the printed microbes through the mail and quickly and easily unlock the message.

It works like so: The team took seven strains of common Escherichia coli bacteria and engineered each to glow a different color under the right light via fluorescent proteins. The bacteria are then grown in pre-selected sequences of paired dots, with each pair representing a letter or other symbol like a numeric digit. These pairs can then be imprinted on a sheet of nitrocellulose and sent through the post like any other piece of paper.

At the other end, the recipient simply has to regrow the bacteria (which isn’t difficult) and place it under the right kind of light or expose it to antibiotics to make it glow, revealing the coded message. Moreover, the bacteria can be further engineered to only express their colors after specific periods of time, or to self-destruct after a certain period in proper Hollywood spy style. They can also be tailored to respond differently to different antibiotics, revealing the true message only when a certain kind of antibiotic--known by the intended recipient--is used.

The drawbacks: there are only a limited number of antibiotics in the world, so it wouldn’t be difficult to brute force a coded message by using all available antibiotics to reveal the true message. But this doesn’t bother the researchers behind the development, as they are less concerned with the cloak and dagger applications of their technology anyhow. They’re more interested in developing new ways to watermark genetically modified organisms with “biological barcodes” to protect intellectual property and make the world safer for modified life.

[Nature]

This research is part of Cronin's larger project to show that inorganic compounds are able to self-replicate and evolve like biological cells do. The ultimate goal is to give these inorganic cells life-like properties so they can evolve and eventually be used in materials science.

Cronin said he believes creating inorganic life is entirely possible, that if biological organisms evolved from single-cell bacteria, so should life be able to evolve from inorganic microorganisms. This “inorganic living technology,” if it works, could change the way we think about evolution, showing that it's not a process exclusive to biology, and that non-carbon-based life could exist.

[BBC]

Wolbachia comes in several flavors--almost all of which manifest themselves in the gonads as well as other organs--but the particular one researchers have identified here has a unique property: when an infected male mates with an uninfected female, the female dies. And when an infected male mates with an infected female, the offspring live--but they all carry the Wolbachia infection with them, ensuring its further spread through a population.

This, of course, solves a major problem with mosquito control. Spraying insects with insecticides helps them to develop resistance to poisons. And biological agents that kill them off don’t proliferate within the population, so the solution is temporary--the next season, new mosquitoes move in and it’s back to square one.

But the Wolbachia-infected mosquitoes go on to live long and fruitful lives, spreading the infection to their offspring as they go. And the bacterial infection has a key trait: it’s really bad at sharing. Where Wolbachia takes hold, it is loathe to give up ground to other infections--like Dengue. Other infectious things, including viruses, just don’t grow well where Wolbachia has already put down roots.

That’s good news. Even better, the researchers have already taken their strain of Wolbachia for a test-drive in two Australian towns. In one town, the infection rate among mosquito populations was nearly total. In the other, it topped 90 percent. There’s plenty more that needs to be learned about Wolbachia and its expression before it can be rolled out more widely--like whether or not the infection will pick up again after the dry season in which mosquito mating behaviors and populations change drastically. But given that Dengue fever touches 50 million people a year, it’s a promising start.

More via the Ars link below.

[Ars Technica]

The first isolated instances of conching were recorded in 2007 and 2009 among a small group of Shark Bay's dolphins. But other dolphins seem to be observing that behavior and learning the method for themselves--in the last four months alone, researchers have documented the behavior six or seven times--marking a very rapid horizontal spread of behavior.

That’s significant on a few levels. For one, we already know dolphins are very intelligent creatures, but a horizontal spread of a learned behavior at this rate is pretty off-the-charts. Moreover, scientists appear to have gotten in on this fad at the ground floor (they were observing dolphins conching way before it was mainstream, bro), so they have the opportunity to observe this learned behavior as it spreads.

There are still a lot of questions about how exactly dolphins execute a good conch. Researchers have seen the end result at the surface, but are curious as to how the behavior unfolds underwater. Do the dolphins manipulate the shells to scoop the fish in, or do they turn them so the opening is facing up and then chase fish into them? If the latter, it suggests a good deal of foresight and premeditation on the part of the dolphins--yet another tantalizing finding for biologists and behaviorists.

As such, researchers at Shark Bay are thinking about setting up underwater experiments and cameras to capture the act of conching from start to finish. Because dude, a conching doesn’t count unless it’s photographed. No word on whether they’ll Instagram the images to make them look vintage before posting them to Facebook.

Meet the 21st amino acid

A quick biology primer, just in case high school biology isn't so fresh. DNA is of course the blueprint for all of our biological stuff. It gives instructions on how the amino acids should arrange themselves into proteins, which pick up the heavy lifting of life from there. There are just 20 amino acids, arranged in different combinations, that are encoded in the genome.

The Cambridge team has created nematode worms that generate a 21st, never before seen amino acid. That’s big, because it basically enables a new resolution in genetic manipulation, a kind of “atom-by-atom control” over biological molecules, as one biologist put it to the BBC.

The artificial protein produced by their artificially enhanced nematodes simply contains a fluorescent dye that glows red under UV light--a test to ensure that their genetic manipulation worked. But ostensibly scientists could do all kinds of things with this technique by producing all kinds of novel amino acids and proteins. Unlike an artificial recreation of something natural--something akin to the Venter Institute’s “synthetic life”--these nematodes represent that creation of something wholly new.

Keep an eye on this story. It’s bursting with potential for mind-blowing scientific innovation and chilling sci-fi screenplays.

[BBC]

This is big news, of course, because if the ingredients for life were brought here from some external source, there’s always the possibility that the same thing has happened elsewhere in the universe--possibly many times over.

Scientists have been extracting fragments of DNA from meteorites for decades now, but there was never really hard proof that those pieces of biological molecules were native to the extraterrestrial object rather than terrestrial contamination that occurred when the object slammed into Earth. So while the idea of DNA riding aboard extraterrestrial objects has been floated before, this is the first time we’ve been presented real evidence backing that notion.

The idea isn’t that these building blocks are just passengers aboard meteorites, but that the chemistry inside asteroids and comets can actually manufacture the essential building blocks of biology. And a liquid chromatography and mass spectrometry analysis of sample meteorites and the environments where they were found seems to confirm this.

Here’s the basic gist of the findings: The LC and MS analysis separated and analyzed the component parts of the samples and found adenine and guanine, two of the components of the double helix that make up the code that tells our cells what to do. They also found hypoxanthine and xanthine, which don’t factor in to DNA but are used in other biological functions.

But more interestingly, the researchers found three nucleobase-related molecules: purine, 2,6-diaminopurine, and 6,8-diaminopurine. These last two are rarely used in biology, but they are like analogs for nucleobases--the same core molecule but structurally slightly different. That’s really important because if the meteorites were terrestrially contaminated, they wouldn’t be there (because they are not used in biology). But if the chemical processes going on inside an extraterrestrial object really are churning out prebiotic stuff, then you would expect to see all kinds of nucleobases--the ones used for biology, and others that aren’t.

Moreover, analysis of the Antarctic ice and Australian soil around where the meteorites were found showed the amounts of the two nucleobases as well as the hypoxanthine and xanthine to be drastically lower. If the contamination were terrestrial, one could expect equal amounts of the molecules (or less) to be present in the meteorite samples, certainly not more.

It’s a pretty convincing case, though one that will undergo a lot more scientific scrutiny. If comets and asteroids really are churning out the ingredients for life, it certainly changes our picture of life in the universe, and the possibility that other rocks out there might be harboring their own biological systems.

[NASA]