Wednesday, May 7, 2014

The Plight of the Penguins

            Everyone loves penguins. From their distinctive waddle, to their tuxedo-like coloration, everyone can recognize these flightless birds. Mostly found on the frozen wastes of Antarctica, penguins are known for their swimming prowess as well as their ability to withstand the frigid conditions of their home. However, trouble looms on the horizon for these birds, as an international research team has discovered a strain of avian flu in the adélie penguin.

The adélie penguin
(Photo credit: George F. Mobley)

            The adélie penguin, Pygoscelis adeliea, is one of the more common species of penguin. Roughly 70 cm tall, these short penguins were discovered in 1840 by James Dumont d’Urville, a French explorer. The adélie penguin is typically found on small islands surrounding the coast of Antarctica, during the spring breeding season. Otherwise, they tend to spend most of their time out at sea, searching for food. Adélie penguins typically will eat krill and other small marine creatures, but will eat small fish and squid as well.
            While these penguins are incredibly good swimmers, reaching speeds of 72 km/hr. and diving to depths of 175 meters, they are also remarkably good walkers as well. Despite having the distinctive penguin waddle, these birds will walk 31 miles to go from their nests to the shoreline. The penguins’ main threat lies from predation by leopard seals and skuas, as well as the occasional orca.
            But there might be a new threat from these little penguins, one that could be much more dangerous, avian flu. This comes as a shock to Dr. Aeron Hurt, a senior researcher for the WHO Collaborating Centre for Reference and Research on Influenza, as no active strain of avian flu had ever been seen in Antarctic birds before. For this study, Hurt and his team collected swabs from the windpipes of 301 penguins and blood from 270 of those birds as well.
            Using real-time reverse transcription PCR, Hurt and his team found avian influenza genetic material in eight of the birds. Four of these viruses were able to be cultured, meaning that they were active and infectious. Not only that, but these strains of influenza all seemed to be H11N2 influenza viruses and were all very similar to each other. Worst of all, when comparing this genetic material to other known strains of influenza, Hurt and his team discovered that this strain was unlike anything they had ever seen before.

Dr. Aeron Hurt with an adélie penguin
(Photo credit: Aeron Hurt)

            Luckily, it seems that currently the virus isn’t doing any damage to the penguins and is not making the birds sick. It also appears to be exclusive to birds, as it couldn’t infect a species of weasel that the researchers used. However, it raises a lot of question for Hurt and his team. Namely, how often are avian influenza viruses being brought into Antarctica, whether animal ecosystems are allowing the virus to sustain itself, and whether or not the virus is being cryopreserved during the winter? For now, all we can try to do is keep trying to find where these virus strains are coming from and trying to find a cure before they mutate into something much more dangerous for the adélie penguin.


Tuesday, May 6, 2014

On the Origins of Life

            Four billion years ago, the Earth was just a floating ball of rock; insanely hot, an atmosphere of carbon dioxide, it’s amazing that life could ever exist here. But as Ian Malcolm said, “Life, uh, finds a way.” And indeed it did. Life started in the oceans of primordial Earth; a soup of amino and nucleic acids, lipids, and carbohydrates that just happened to be in the right place at the right time to become the original cell. Many believed that a bolt of lightning might have provided the original energy needed for this transformation, but a new study presents another possible origin.
            Recently, NASA scientists believe they may have found what provided the electrical energy needed to create life. Deep down on the bottom of the ocean floor, hydrothermal vents are spewing out sulfur, magma, and apparently, electricity. The hypothesis was first proposed under the name “submarine alkaline hydrothermal emergence of life”, but NASA has now managed to unify all of the data into one unified picture.

A "Black Smoker" Vent
(Photo credit: NOAA)

            But not every hydrothermal vent produces the conditions needed to create life. While it was assumed in the 1980’s when the hypothesis was first proposed that “black smokers”, vents that produce extremely hot, acidic water, were responsible, but this may not be the case. The vents that NASA scientists use in their new study produce cooler, alkaline water and are not nearly as harsh.

An alkaline vent, dubbed "The Lost City"
(Photo credit: The University of Washington)

            Michael Russell, the head scientist for this study, states that these alkaline vents created an unbalanced state, conflicting with the ancient acidic oceans. This imbalance created the free energy needed to create life, Russell believes. In fact, Russell believes that these vents could have created two imbalances.
            The first imbalance was a proton imbalance. This would have been caused by the alkaline fluids interacting with the acidic oceans that surround them. This gradient could have been used to produce energy in a fashion similar to how mitochondria function. The other imbalance could have been an electrical imbalance. The ancient oceans were loaded with carbon dioxide, which when coming into contact with the methane producing vent could have become more advanced carbon compounds, which are important for the formation of life.
            But life isn’t just electricity and carbohydrates, proteins are also needed. Will in the primordial soup that was Earth’s ancient ocean, enzymes could be found floating in the water. These enzymes could then come into contact with the rock chimneys of these alkaline vents, where two different “protein engines” could take over.
            The first would have harnessed the proton gradient from earlier in order to produce energy storing molecules which could be used later. The other used an element known as molybdenum, which can allow for the transfer of two electrons at once instead of one; a key concept needed in most key chemical reactions.

            So, this study presents a lot of interesting information. We now have a practical, new idea on the origins of life. This information could be applied to any rocky, wet planet in terms of identifying if life could exist there. So, while we are still not terribly certain on how life started on Earth, we now have a good idea of what may have happened. And while it may take decades to truly figure out how life started, Russell and his team while be willing to tackle these problems until they’re solved.


Monday, May 5, 2014

Battles Under the Sea

            A battle under the sea brings up iconic images; sharks and whales and other large animals fighting for their lives. However, this battle occurs deeper than what these animals could reach; roughly one mile below the ocean to be specific. In the deep darkness of the bathypelagic, a war is happening…a microbial war. It’s been recently discovered that viruses are attacking hydrothermal bacteria with one goal, their stores of sulfur.

A typical hydrothermal vent 
(Photo credit: NOAA)

            Bacteria and viruses have been enemies for as long as both have existed, but this is anew an interesting front in these battles. Deep-sea hydrothermal bacteria are still very unusual and not very well-known, and this is the first time that this sort of virus-bacteria relationship has been seen, since chemosynthetic bacteria are a rare lot.
            So, why do these bacteria target the sulfur in these bacteria? Well, the answer lies in the viruses’ desire to reproduce; turning the bacteria into a virus factory in a sense. What they do is they will force the bacteria to consume all of its sulfur reserves, and then use the resulting energy to create as many viruses as possible. The bacteria will inevitably die from this process, releasing all of the newly created viruses into the open to repeat the process.
            Interestingly enough, this sort of relationship has been seen before, namely in the shallow ocean water. There is a similar virus that target photosynthetic bacteria in order to reach the same end goal. So, it’s interesting to see the parallel between the two viruses, especially when it comes to their mechanism for reproducing.
            So, what are researchers doing about this? Well, currently Gregory Dick, a University of Michigan microbiologist and oceanographer, and his team are currently analyzing the DNA of the bacteria and viruses in order to better understand the mechanism of this invasion. After collecting samples from the hydrothermal vents found near the Gulf of California and the Western Pacific, Dick has begun taking a look at the DNA samples he’s gathered, and believes he may have found what the virus is doing.
            Dick and his team believe that the virus is targeting the SUP05 genes found in the bacteria. This comes as no surprise to Dick, as the SUP05 genes are responsible for creating the proteins necessary to use sulfur to create energy. By targeting this gene, the virus can overexpress it, forcing the bacteria to burn through its supply of sulfur faster than it would ever need to naturally.

Riftia pachyptila, a polychaete typically found around hydrothermal vents have an organ with chemosynthetic bacteria instead of a gut.
(Photo credit: Wikimedia Foundation)

            So, what does this mean, what can be gained from this research? Well, Dick believes that this shows that these viruses are actually very important in the long term survivability of these bacteria. Dick and his team believe that these viruses act as “agents of evolution”, allowing for gene transfer between the chemosynthetic bacteria, a theory first proposed about photosynthetic bacteria found in the shallows by David Garrison, a program director for the National Science Foundation. Without these viruses, the bacteria would rarely receive gene transfer, and a disease could cause catastrophic damage to the bacterial population, which could cause an entire collapse of the hydrothermal vent community, since they rely on these bacteria for primary production.