Showing posts with label Life-Forms. Show all posts
Showing posts with label Life-Forms. Show all posts

Friday, February 3, 2017

Scientists have created new forms of life containing '' Artificial DNA'' This could be the beginning of a whole new life form.

Credit: Kateryna Kon
Scientists have engineered the first ever 'semi-synthetic' organisms, by breeding E. coli bacteria with an expanded, six-letter genetic code.

While every living thing on Earth is formed according to a DNA code made up of four bases (represented by the letters G, T, C and A), these modified E. coli carry an entirely new type of DNA, with two additional DNA bases, X and Y, nestled in their genetic code.

The team, led by Floyd Romesberg from the Scripps Research Institute in California, engineered synthetic nucleotides - molecules that serve as the building blocks of DNA and RNA - to create an additional base pair, and they’ve successfully inserted this into the E. coli’s genetic code.

Credit: samsunkenthaber

Now we have the world’s first semi-synthetic organism, with a genetic code made up of two natural base pairs and an additional 'alien' base pair, and Romesberg and his team suspect that this is just the beginning for this new form of life.

"With the virtually unrestricted ability to maintain increased information, the optimised semi-synthetic organism now provides a suitable platform  to create organisms with wholly unnatural attributes and traits not found elsewhere in nature," the researchers report.

"This semi-synthetic organism constitutes a stable form of semi-synthetic life, and lays the foundation for efforts to impart life with new forms and functions."

Back in 2014, the team announced that they had successfully engineered a synthetic DNA base pair - made from molecules referred to as X and Y - and it could be inserted into a living organism.


Since then, they’ve been working on getting their modified E. coli bacteria to not only take the synthetic base pair into their DNA code, but hold onto it for their entire lifespan.

Initially, the engineered bacteria were weak and sickly, and would die soon after they received their new base pair, because they couldn’t hold onto it as they divided.

Credit: Wonderwhizkids

"Your genome isn't just stable for a day," says Romesberg. "Your genome has to be stable for the scale of your lifetime. If the semisynthetic organism is going to really be an organism, it has to be able to stably maintain that information."

Over the next couple of years, the team devised three methods to engineer a new version of the E. coli bacteria that would hold onto their new base pair indefinitely, allowing them to live normal, healthy lives.

The first step was to build a better version of a tool called a nucleotide transporter, which transports pieces of the synthetic base pair into the bacteria’s DNA, and inserts it into the right place in the genetic code. 

"The transporter was used in the 2014 study, but it made the semisynthetic organism very sick," explains one of the team, Yorke Zhang.

Once they’d altered the transporter to be less toxic, the bacteria no longer had an adverse reaction to it.

Next, they changed the molecule they’d originally used to make the Y base, and found that it could be more easily recognised by enzymes in the bacteria that synthesise DNA molecules during DNA replication.

Finally, the team used the revolutionary gene-editing tool, CRISPR-Cas9 to engineer E. coli that don’t register the X and Y molecules as a foreign invader.

The researchers now report that the engineered E. coli are healthy, more autonomous, and able to store the increased information of the new synthetic base pair indefinitely.

"We've made this semisynthetic organism more life-like," said Romesberg.

If all of this is sounding slightly terrifying to you, there's been plenty of concern around the potential impact that this kind of technology could have.


Back in 2014, Jim Thomas of the ETC Group, a Canadian organisation that aims to address the socioeconomic and ecological issues surrounding new technologies, told the New York Times:

"The arrival of this unprecedented 'alien' life form could in time have far-reaching ethical, legal, and regulatory implications. While synthetic biologists invent new ways to monkey with the fundamentals of life, governments haven’t even been able to cobble together the basics of oversight, assessment or regulation for this surging field."

And that was when the bacteria were barely even functioning. 

But Romesberg says there's no need for concern just yet, because for one, the synthetic base pair is useless. It can't be read and processed into something of value by the bacteria - it's just a proof-of-concept that we can get a life form to take on 'alien' bases and keep them.

The next step would be to insert a base pair that is actually readable, and then the bacteria could really do something with it.

The other reason we don't need to be freaking out, says Romesberg, is that these molecules have not been designed to work at all in complex organisms, and seeing as they're like nothing found in nature, there's little chance that this could get wildly out of hand.

"[E]volution works by starting with something close, and then changing what it can do in small steps," Romesberg told Ian Sample at The Guardian.

"Our X and Y are unlike natural DNA, so nature has nothing close to start with. We have shown many times that when you do not provide X and Y, the cells die, every time."


Time will tell if he's right, but there's no question that the team is going to continue improving on the technique in the hopes of engineering bacteria that can produce new kinds of proteins that can be used in the medicines and materials of the future.


The research has been published in Proceedings of the National Academy of Sciences.


Other articles on the same theme:




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The above post is reprinted from materials provided by Sciencealert . Note: Materials may be edited for content and length.

Tuesday, January 31, 2017

Researchers are close to discover the factor that determined the evolution of life on Earth

Credit: klss/Shutter Stock
Modern science has advanced significantly over the last couple of decades. We’ve managed to answer several of the world’s most long-standing questions, but some answers have continued to elude today’s scientists, including how life first emerged from Earth’s primordial soup.

However, a collaboration of physicists and biologists in Germany may have just found an explanation to how living cells first evolved.

In 1924, Russian biochemist Alexander Oparin proposed the idea that the first living cells could have evolved from liquid droplet protocells.

He believed these protocells could have acted as naturally forming, membrane-free containers that concentrated chemicals and fostered reactions.

Aleksandr Oparin (right) and Andrei Kursanov in the enzymology laboratory, 1938 Credit: wikipedia

In their hunt for the origin of life, a team of scientists from the Max Planck Institute for the Physics of Complex Systems and the Institute of Molecular Cell Biology and Genetics, both in Dresden, drew from Oparin’s hypothesis by studying the physics of 'chemically active' droplets (droplets that cycle molecules from the fluid in which they are surrounded).

Unlike a 'passive' type of droplet - like oil in water, which will just continue to grow as more oil is added to the mix - the researchers realised that chemically active droplets grow to a set size and then divide on their own accord.

This behaviour mimics the division of living cells and could, therefore, be the link between the nonliving primordial liquid soup from which life sprung and the living cells that eventually evolved to create all life on Earth.

"It makes it more plausible that there could have been a spontaneous emergence of life from nonliving soup," said Frank Jülicher, co-author of the study that appeared in the journal Nature Physics in December.

It’s an explanation of "how cells made daughters," said lead researcher David Zwicker. "This is, of course, key if you want to think about evolution."


Add a droplet of life

Some have speculated that these proto-cellular droplets might still be inside our system "like flies in life’s evolving amber".

To explore that hypothesis, the team studied the physics of centrosomes, which are organelles active in animal cell division that seem to behave like droplets.

Zwicker modelled an 'out-of-equilibrium' centrosome system that was chemically active and cycling constituent proteins continuously in and out of the surrounding liquid cytoplasm.

The proteins behave as either soluble (state A) or insoluble (state B).  An energy source can trigger a state reversal, causing the protein in state A to transform into state B by overcoming a chemical barrier. 

As long as there was an energy source, this chemical reaction could happen.

"In the context of early Earth, sunlight would be the driving force," Jülicher said.

Odarin famously believed that lighting strikes or geothermal activity on early Earth could’ve triggered these chemical reactions from the liquid protocells.

This constant chemical influx and efflux would only counterbalance itself, according to Zwicker, when a certain volume was reached by the active droplet, which would then stop growing.

Typically, the droplets could grow to about tens or hundreds of microns, according to Zwicker’s simulations. That’s about the same scale as cells.

The next step is to identify when these protocells developed the ability to transfer genetic information.

Jülicher and his colleagues believe that somewhere along the way, the cells developed membranes, perhaps from the crusts they naturally develop out of lipids that prefer to remain at the intersection of the droplet and outside liquid.

Credit: Lucy Reading-Ikkanda/Quanta Magazine
As a kind of protection for what’s within the cells, genes could’ve begun coding for these membranes. But knowing anything for sure still depends on more experiments.

So, if the very complex life on Earth could have begun from something as seemingly inconspicuous as liquid droplets, perhaps the same could be said of possible extraterrestrial life?

In any case, this research could help us understand how life as we know it started from the simplest material and how the chemical processes that made our lives possible emerged from these.

The energy and time it took for a protocell to develop into a living cell, and the living cells into more complex parts, until finally developing into an even more complex organism is baffling.

The process itself took billions of years to happen, so it’s not surprising we need some significant time to fully understand it.

Other articles on the same theme:



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The above post is reprinted from materials provided by Sciencealert . Note: Materials may be edited for content and length.

Thursday, July 7, 2016

Back to Europa! ALIEN OCEAN NEXT NASA'S MISSION TO EUROPA






















Updated: 28/04/2020  

Possible Life similarities between Jupiter's moon Europa and depths of the Oceans on Earth

NASA’s next mission back to Jupiter’s moon Europa just took another big step towards reality. The next phase of Europa Clipper has been confirmed, giving the go-ahead for the mission to proceed to final design, construction and testing.

“We are all excited about the decision that moves the Europa Clipper mission one key step closer to unlocking the mysteries of this ocean world,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. “We are building upon the scientific insights received from the flagship Galileo and Cassini spacecraft and working to advance our understanding of our cosmic origin, and even life elsewhere.”




Europa Clipper will be the first spacecraft to study Europa up close since Galileo in the early 2000s, and will focus on determining the habitability of the moon’s global subsurface ocean. That ocean is thought to be quite similar to oceans on Earth, although it is completely covered by an outer ice crust. But thanks to previous studies, scientists know that it is salty with a rocky ocean bottom likely rich in chemical nutrients that life could use for food and energy. There may even be hydrothermal activity similar to the vents on the ocean bottoms of Earth. Such hot spots can be an oasis for a wide variety of life forms, even at great depths with no light.

Below Europa’s cold, icy surface lies a deep, salty liquid water ocean which could be home to some form of life. Image Credit: Britney Schmidt/Dead Pixel VFX/Univ. of Texas at Austin

That ocean makes Europa one of the best places in the Solar System to search for evidence of extraterrestrial life, along with Saturn’s moon Enceladus, which although smaller, also has a global subsurface ocean under its icy surface.

Artist’s conception of the Europa lander, which had been considered as part of the Europa Clipper mission, but now will probably be a follow-up mission at a later date. Image Credit: NASA/JPL-Caltech


Enceladus has huge water vapor plumes that erupt from cracks in the surface near the south pole. The Cassini spacecraft sampled those plumes directly and found they contain water, salts and both simple and complex organic molecules. The plumes originate from the ocean below, so this analysis provides clues as to the conditions in the ocean and how habitable it is. Enceladus’ ocean also appears to be very similar to Earth’s oceans, and there is even more evidence for active hydrothermal vents on the ocean floor.

An example of possible spectroscopy results from the James Webb Space Telescope of one of Europa’s water vapor plumes. Image Credit: NASA-GSFC/SVS/Hubble Space Telescope/Stefanie Milam/Geronimo Villanueva















Europa may also have similar plumes, but they have been more difficult to confirm since they seem to be smaller and more intermittent. New evidence for them from the Hubble Space Telescope was announced last year, however. Americaspace


ALIEN OCEAN NEXT NASA'S MISSION TO EUROPA

SAN FRANCISCO — There's a good chance that NASA's highly anticipated Europa mission will do much more than just fly by the ocean-harboring Jupiter moon.

NASA has already selected the nine primary science instruments for the Europa (moon) spacecraft, whose core mission involves performing dozens of flybys to gauge the Jovian satellite's life-hosting potential. But the probe should be able to accommodate an additional 550 lbs. (250 kilograms) of payload, and NASA would rather not let that "excess" go to waste.

"There's a variety of things that we can do," Jim Green, the head of NASA's Planetary Science division, said here Tuesday (Dec. 15) during a town hall presentation at the annual fall meeting of the American Geophysical Union (AGU). "Perhaps plume probes, perhaps penetrators, or even a small lander." [Europa May Harbor Simple Life-Forms (Video)]





There's no guarantee that any additional instruments or miniprobes will make it onboard the Europa spacecraft. But the smart money may be on one or two ultimately being selected.

"We're pretty hot on doing something," Green told Space.com after his presentation.

The 1,900-mile-wide (3,100 kilometers) Europa is regarded as one of the solar system's best bets to host alien life. Though Europa is covered by an ice shell perhaps 50 miles (80 km) thick, the satellite also harbors a huge subsurface ocean that contains more water than all of Earth's seas combined.

This ocean is in contact with Europa's rocky mantle, making possible a range of interesting and complex chemical reactions, researchers say.

The $2 billion Europa mission, which does not have an official name yet, aims to investigate the habitability of the moon and its ocean.

The spacecraft is scheduled to launch in the early to mid-2020s and reach the Jupiter system 8 years later, if a "standard" rocket such as United Launch Alliance's Atlas V serves as the launch vehicle. (Using NASA's in-development Space Launch System megarocket would slash the travel time to 3 years or so, Green said.)

The probe would then perform 45 flybys of Europa over the next 2.5 years or so, studying the satellite with high-resolution cameras, a heat detector, ice-penetrating radar and other scientific gear.

None of the nine already-announced instruments were designed to hunt for signs of life. But it's possible that a small deployable plume probe — which would fly through putative plumes of water vapor near Europa's south pole, which were detected in December 2012 but have yet to be confirmed by follow-up observations — could carry life-detecting gear. So could a penetrator, which would slam into Europa's ice shell at high speeds, or a lander, which would touch down softly.

Europa's rough and rugged terrain — a complex jumble of big ice cliffs and crevasses — would make a soft landing extremely challenging, Green said, and surface work would be tough in the moon's high-radiation environment (though radiation levels aren't uniform across Europa, and analyses suggest that a lander could operate for extended periods in some locales, Green added).


We'll all just have to wait and see if NASA will add these challenges to its Europa to-do list.


Over the centuries, Europa, the most luminous of all the Galilean moons, has provided an abundance of mysteries. These culminated in what may have been a literal explosion in December 2012, when a cloud of water vapor was seen 20 miles over its south pole. This eruption was tiny on the cosmic scale, but enormous in its importance to astrobiology.




Notothenioidei is one of 18 + 1 new suborders from the order Perciformes and includes Antarctic icefish and sub-Antarctic fish. Notothenioids are distributed mainly throughout the Southern Ocean around the coasts of New Zealand, South America, and Antarctica

Evolution and geographic distribution

The Southern Ocean has supported fish habitats for 400 million years; however, modern notothenioids likely appeared sometime after the Eocene epoch. This period marked the cooling of the Southern Ocean, resulting in the stable, ice-cold conditions that have persisted to present day, excepting abrupt, rapid warming in the region in recent years. Another key factor in the evolution of notothenioids is the preponderance of the Antarctic Circumpolar Current (ACC), a large, slow-moving current that extends to the seafloor and precludes most migration to and from the Antarctic region

Alien Antarctic Fish pixelx


These unique environmental conditions in concert with the key evolutionary innovation of Antifreeze glycoprotein promoted widespread radiation within the suborder, leading to the rapid development of new species wikipedia


Amphipod sand hopper

Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from 1 to 340 millimetres (0.039 to 13 in) and are mostly detritivores or scavengers.



There are more than 9,900 amphipod species so far described. They are mostly marine animals, but are found in almost all aquatic environments. Some 1,900 species live in fresh water, and the order also includes terrestrial animals and sandhoppers such as Talitrus saltator.


The body of an amphipod is divided into 13 segments, which can be grouped into a head, a thorax and an abdomen. The head is fused to the thorax, and bears two pairs of antennae and one pair of sessile compound eyes. It also carries the mouthparts, but these are mostly concealed.


Diagram of the anatomy of the gammaridean amphipod Leucothoe incisa wikipedia


The thorax and abdomen are usually quite distinct and bear different kinds of legs; they are typically laterally compressed, and there is no carapace. The thorax bears eight pairs of uniramous appendages, the first of which are used as accessory mouthparts; the next four pairs are directed forwards, and the last three pairs are directed backwards. Gills are present on the thoracic segments, and there is an open circulatory system with a heart, using haemocyanin to carry oxygen in the haemolymph to the tissues. The uptake and excretion of salts is controlled by special glands on the antennae.

The abdomen is divided into two parts: the pleosome which bears swimming legs; and the urosome, which comprises a telson and three pairs of uropods which do not form a tail fan as they do in animals such as true shrimp. wikipedia



Anglerfish 

Anglerfishes are fish of the teleost order Lophiiformes.They are bony fish named for their characteristic mode of predation, in which a fleshy growth from the fish's head (the esca or illicium) acts as a lure.

Some anglerfish are notable for extreme sexual dimorphism and sexual symbiosis of the small male with the much larger female, seen in the suborder Ceratioidei. In these species, males may be several orders of magnitude smaller than females.



Anglerfish occur worldwide. Some are pelagic (dwelling away from the sea floor), while others are benthic (dwelling close to the sea floor). Some live in the deep sea (e.g., Ceratiidae), while others on the continental shelf (e.g., the frogfishes Antennariidae and the monkfish/goosefish Lophiidae). Pelagic forms are most laterally compressed, whereas the benthic forms are often extremely dorsoventrally compressed (depressed), often with large upward-pointing mouths. wikipedia




















The above post is reprinted from materials provided by Mike Wall. Note: Materials may be edited for content and length.â