Monday, January 30, 2012
Thursday, January 12, 2012
Written by Mitch Leslie
An octopus dwelling in the frigid waters of the Antarctic doesn’t wear gloves on its tentacles, but it has found another way to endure the cold. A new study shows that this animal uses a trick called RNA editing to customize crucial nervous system proteins to work at low temperatures. The paper is the first to reveal that RNA editing, not just changes to a specific gene, can lead to adaptations.
Low temperatures hamper certain proteins that allow the nervous system to send signals. When a nerve cell fires, protein channels in its membrane open or close to allow various ions in or out. And when the electrical charge across the cell membrane returns to normal, the ion channels that let potassium ions out shut. But frigid temperatures can delay the potassium channels’ closing, hindering the neuron’s ability to fire again. So researchers hypothesized that species inhabiting frigid climates have modified their potassium channels so they work better in the cold.
Molecular neurophysiologist Joshua Rosenthal of the University of Puerto Rico Medical Sciences Campus in San Juan and his graduate student Sandra Garrett figured they knew how that adjustment would occur. “We thought we were going to see changes at the level of the gene,” Rosenthal says. That is, they expected the potassium channel genes from cold-living species would have evolved so that they produce a slightly different protein that performs better at low temperatures.
The pair recently tested their suspicion by comparing an octopus species that lives in frigid Antarctic seas with another dwelling on a Puerto Rican reef where the water ranges from 25° to 35°C. To their surprise, they found that the potassium channel genes in the two species had almost identical DNA sequences. Next, the researchers inserted the genes into frog egg cells, which then manufactured each protein and installed it in their plasma membrane. This procedure allowed the researchers to measure the electrical activity of each species’ channel.
Rosenthal and Garrett discovered that when made by the frog eggs, the potassium channels from the two species functioned much the same. As a result, the pair calculated, if the two species made these versions of the potassium channels in their respective habitats, the Antarctic octopus’s channel would close 60 times slower than that of its Puerto Rican counterpart.
So how does the polar creature keep its nerve cells firing normally? There’s another way, RNA editing, to change a protein. To make the protein coded for by a gene, cells synthesize an RNA version of the DNA that serves as a blueprint to construct the protein. During RNA editing, cells amend the nucleotide sequence of the RNA, which can alter the sequence of amino acids in the resulting protein and change the protein’s function. The Antarctic octopus edits its RNA at nine sites that change the amino acid sequence of the potassium channel, the researchers report online today in Science. One of these sites, known as I321V, was particularly important for adapting to the cold: The change more than doubles the potassium channel’s closing speed.
The researchers also gauged the amount of RNA editing in two more tropical species, two temperate species, and two species that live in the Arctic. The colder the species’ habitat, the more likely it was to make RNA edits at the I321V site. “What our paper really adds,” Rosenthal says, “is that this process can be used to help adapt to the environment.”
Other researchers praise the study for revealing a new way for organisms to adapt. “There’s this whole different molecular mechanism for increasing protein diversity,” says molecular neurobiologist Ronald Emeson of the Vanderbilt University Medical Center in Nashville. Whether RNA editing shapes other traits is the next question to answer, adds geneticist Brenton Graveley of the University of Connecticut Health Center in Farmington. The paper “sets the stage for showing that RNA editing can have a big role in adaptation,” he says.
This story provided by ScienceNOW, the daily online news service of the journal Science.
Tuesday, January 10, 2012
Bryce hooked into a octopus which he originally thought was a snag. I was able to get some pretty sweet underwater shots while it was next to his kayak. The octopus was kept and enjoyed. It swallowed a pretty large hook so its survival was unlikely. I used a Kodak Playsport (Zx3) to film this.
Further info for the people commenting: For the record, I didn't kill it, or eat it. I just filmed it. Also, it was not wasted. Its sacrifice was well respected among those that did eat it. I'm not a biologist of any kind, but a simple search on the internet shows that octopuses are not a rare animal. In fact, there is evidence that suggests they are overpopulated in their range. They have a life-span of 3 to 5 years so I'm guessing because of its size that this one was nearing the end of that span. So, I would rather it be killed quickly and not wasted than it be set free to suffer and starve for the last year or so of its life with a six inch hook in its mouth.
Monday, January 9, 2012
I've found this mug available on many sites, although the least expensive I've discovered has been a favorite fun stuff resource of mine, McPhee.com.
"Our team of scientists has just recently discovered a new species of cephalopod, the mug-dwelling octopus. This tentacled, porcelain mollusk prefers the cozy confines of a simple coffee mug to the vast depths of the ocean. Each 3-1/4" tall, porcelain mug features one of these odd little octopuses on the bottom. Great for coffee, tea or ramen noodles! Dishwasher and microwave safe."
The octopus mug comes in a neato box too!
I highly recommend this octopus mug as a gift - to yourself or a fellow ceph-lover!
Thursday, January 5, 2012
guardian.co.uk, Wednesday 4 January 2012
A world of previously unseen creatures has been found thriving next to boiling vents of water, several miles under the surface of the Southern Ocean near Antarctica. Hundreds of hairy-chested yeti crabs, a mysterious-looking pale octopus and colonies of limpets, snails and barnacles were found by British scientists at a hydrothermal vent located in the ocean's East Scotia Ridge.
Prof Alex Rogers of Oxford University used a remotely operated vehicle called Isis to scout the sea bed around the ridge, which spans about 2.4km and features springs of black, smoky water that can reach temperatures of almost 400C (752F). The hydrothermal vents are powered by underwater volcanoes, and the scalding temperatures and rich mineral content of the water gives rise to vast rocky chimneys that support a wide variety of life forms.
An image of some of the thriving life found beneath the Southern Ocean. Photograph: Oxford University/PA "The visually dominant species are the yeti crabs, which occur in fantastically high densities, up to 600 per square metre around the southern ridge," said Rogers, who led the expedition aboard the RSS James Cook in January 2010. "Also high densities of stalked barnacles, a large snail from a group called the peltospiroids, and we've also got small, green limpets which occur all over the vents."
The first-known yeti crab, Kiwa hirsuta, was described living near a hydrothermal vent in the south pacific in 2005 and, since then, several species have been discovered in different parts of the undersea world. Around other hydrothermal vents, however, these creatures tend occur in lower numbers; and the new species found in the ESR are not only more numerous but also visually distinct.
"Hirsuta has long hairs on its limbs and its claws, whereas our yeti crabs have extremely hairy chests. One of the nicknames of the crabs which developed during the cruise was the Hasselhoff crabs because they had these dense mats of [hair] on their undersides, the equivalents of their chests."
Another striking creature spotted by the scientists was a pale octopus, which was photographed by the team. Rogers suspected it might be a new species related to the Vulcanoctopus hydrothermalis seen at other underwater vents around the world.
In total, the expedition brought back more than 12,000 samples of rocks, bacteria and animals. Rogers said: "One of the staggering things we did find is that these vents are completely different to those seen anywhere else – the animals existing at these vents are almost all new to science," he said. The findings were published on Tuesday in the journal PLoS Biology.
"What we didn't find is almost as surprising as what we did," said Rogers. "Many animals such as tubeworms, vent mussels, vent crabs, and vent shrimps, which are found in hydrothermal vents in the Pacific, Atlantic, and Indian Oceans, simply weren't there."
Last week, scientists at the University of Southampton announced the discovery of new creatures in the so-called "Dragon Vent" in the south-west Indian Ocean.
Dr Jon Copley, a marine biologist at the University of Southampton who led the exploration of the Dragon Vent and is also an author on the latest PLoS Biology research paper, said that exploration of the world's deep-sea vents was a race against time.
"The exploitation of the deep ocean is overtaking its exploration. We're fishing in deeper and deeper waters, oil and gas is moving into deeper waters and now there's mining starting to take place in deep waters. We need to understand how species disperse and evolve in the deep oceans if we're going to make responsible decisions about managing their resources."
Rogers added that the vents revealed much about how deep water communities have evolved, and how they are distributed across the world's oceans. "In the space of a single eight-week cruise, we've changed our level of understanding of these systems completely. We've changed our ideas about how vent systems are distributed and the factors that may influence that distribution. What that tells us is that our level of knowledge of the deep sea in general is extremely poor indeed."
He added that hydrothermal vents had already changed the way scientists thought about how life exists on earth. "They told scientists that life could exist in the absence of sunlight – you could have food webs based on mechanical energy. They were also informative about the extreme conditions under which life could exist, they told us about where else in the universe life may occur. Hydrothermal vent biology has stimulated a whole new science of astrobiology."
Wednesday, January 4, 2012
Monday, January 2, 2012
January 2, 2012
Hundreds of Occupy the Rose Parade protesters marched down Colorado Boulevard in Pasadena on Monday after the real event was over, lining up behind police squad cars, tow trucks and the last official float to carry their message of economic inequality.
The reaction from the crowd, which was dispersing, was mixed, with some boos, but most people watched quietly or with amusement.
A member of a small group called the Bible Believers, which marches every year at the end of the parade, yelled to the Occupiers: "You people are no more than communist revolutionaries who destroy our country."
When on Occupier started to respond, a member of the movement's "peacekeeping" team stopped him and said he would be better off marching than arguing. The team was formed by the protesters to prevent confrontations.
Most of the occupiers marched carrying banners and homemade signs. A couple of dozen teamed up to carry a human float called "Occupy Octopus" -- a head and eight tentacles made of plastic bags attached to a frame. Sara Daleider of Boyle Heights helped with one of the octopus' tentacles. "It's really a powerful thing to be connected to other people ... and to walk in this really popular parade," she said.
Some occupiers carried a 250-foot preamble to the Constitution written on a tarp with signatures of Occupy protesters on it. Another tarp made to look like a preamble began with the words "We the Corporation."
A group of people on an apartment balcony cheered and waved, as did people in the grandstands. One man yelled, "Get a job!" and "You guys had your 15 minutes."
Roger Bruce of San Clemente, a member of the peacekeeping group, called the march "awesome. It's much bigger than we anticipated." The peacekeepers had no confrontations, only a few nasty comments from onlookers, he said.
Protester Art Goldberg, 70, of Echo Park told a young woman as he walked past: "Don't watch history, make it."
She crossed under the yellow caution tape and joined the march.