Scientists have discovered Antarctic krill (Euphausia superba) living and feeding down to depths of 3000 metres in the waters around the Antarctic Peninsula. Until now this shrimp-like crustacean was thought to live only in the upper ocean. The discovery completely changes scientists’ understanding of the major food source for fish, squid, penguins, seals and whales.

Reporting recently in Current Biology, scientists from British Antarctic Survey (BAS) and the National Oceanography Centre, Southampton* (NOCS) describe how they used a deep-diving, remotely operated vehicle (RoV ) known as the Isis to film previously unknown behaviour of krill.

Professor Andrew Clarke of the British Antarctic Survey said, “While most krill make their living in the ocean’s surface waters, the new findings revise significantly our understanding of the depth distribution and ecology of Antarctic krill. It was a surprise to observe actively-feeding adult krill, including females that were apparently ready to spawn, close to the seabed in deep water.”

Scientists have been studying krill since the ‘Discovery’ expeditions of the early 20th century. Oceanographic expeditions, using a combination of echo-sound techniques and collection samples in nets, indicated that the bulk of the population of adult krill is typically confined to the top 150 metres of the water column.

The grant to purchase the Isis RoV was led by Professor Paul A Tyler of NOCS. He says,”Having the ability to use a deep-water ROV in Antarctica gave us a unique opportunity to observe the krill and also to observe the diversity of animals living at the deep-sea floor from depths of 500m down to 3500m. The importance of such observations is that, not only do we have the ability to identify species, but we can see the relations among individual species and their relationship to the ambient environment.”

The discovery holds some important lessons, Clarke continued. “The behaviour of marine organisms - even quite ‘primitive’ ones - can be complex and more varied than we usually assume. There is still a great deal to learn about the deep sea and an important role for exploration in our attempts to understand the world we live in.”

About Antarctic krill

Antarctic krill (Euphausia superba), feed on phytoplankton and are in turn eaten by a wide range of animals including fish, penguins, seals and whales. Phytoplankon are the starting point for the marine food chain and use photosynthesis to extract carbon from carbon dioxide.

Krill live in the open ocean, mainly in large swarms and reach particularly high numbers in Antarctica. Antarctic krill can grow up to a length of 6cm and can live for 5-6 years. They are one of the largest protein resources on Earth and can be fished easily with large nets for human consumption. The total weight of Antarctic krill is calculated between 50-150 million tonnes.

Numbers of Antarctic krill appear to have dropped by about 80% since the 1970s. The most likely explanation is a dramatic decline in winter sea-ice. Krill feed on the algae found under the surface of the sea-ice, which acts as a kind of ‘nursery’. The Antarctic Peninsula, a key breeding ground for the krill, has warmed by 2.5°C in the last 50 years, with a striking decrease in sea-ice. It is not fully understood how the loss of sea-ice there is connected to the warming, but could be behind the decline in krill.

The article, “Antarctic krill feeding at abyssal depths” by Andrew Clarke and Paul Tyler is published in Current Biology the week of February 25, 2008.

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APS-1 is an rare hereditary disease where the immune system attacks the body’s own organs. Within the framework of a major EU project, coordinated by Professor Olle Kämpe at Uppsala university, scientists have now managed to identify a protein that opens new possibilities of understanding both APS-1 and other autoimmune disorders.

The newly discovered protein, which goes by the name of NALP5, constitutes the target for the immune system’s attacks on the parathyroid glands in the disease APS-1. This finding enables researchers to more closely study the first phase of autoimmune disorders in general, where immune cells, instead of attacking alien bacteria and viruses, erroneously attack the body’s own tissue.

The protein functions as a target for the immune cells in humans, but also in animal models for the disease that have the same genetic defect as APS-1 patients.

“This means now, for the first time, in an experimental situation we will be able to compare the immune defense with exactly the same target protein in humans and in an animal model,” says Mohammad AliMohammadi at the Department of Medical Sciences, Uppsala University, who made the discovery.

The parathyroid glands are the most recently described anatomical structures in humans. They were discovered in 1879 by scientists at Uppsala University and regulate the body’s calcium balance. The fact that the protein NALP5 was found in the parathyroid glands enhances our understanding of their functions. In the long run this discovery can make it possible to develop drugs and treatment methods for diseases producing disturbances in the calcium balance, such as osteoporosis.

In patients with APS-1 the parathyroid glands can be knocked out at a very young age, which can lead to severe cramp attacks that regular cramp treatment is powerless to alleviate. If the disease is not discovered, it therefore often leads to death. The new discovery also makes it possible to diagnose the disease early, so that patients can receive the appropriate treatment.

The discovery is being published in the American journal The New England Journal of Medicine. http://content.nejm.org/cgi/content/short/358/10/1018

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Researchers at UC Riverside have found a way to get into your body and your bloodstream. No, they’re not spiritual gurus or B-movie mad scientists. Nathaniel G. Portney, Yonghui Wu, Stefano Lonardi, and Mihri Ozkan from UCR’s departments of Bioengineering, Computer Science and Engineering, Biochemistry, and Electrical Engineering, and the Center for Nanoscale Science and Engineering, are just talented when it comes to manipulating DNA.

The researchers discovered a system to encode digital information within DNA. This method relies on the length of the fragments obtained by the partial restriction digest rather than the actual content of the nucleotide sequence. As a result, the technology eliminates the need to use expensive sequencing machinery.

Why is this discovery important? The human genome consists of the equivalent of approximately 750 megabytes of data – a significant amount of storage space. However, only about three percent of DNA goes into composing the more than 22,000 genes that make us what we are. The remaining 97 percent leaves plenty of room to encode information in a genome, allowing the information to be preserved and replicated in perpetuity.

Given the size of the DNA fragments (one base pair of DNA is 0.33 nanometers), one could store a large amount of information in a very small space. By storing messages within DNA, organizations can “tag” objects to verify authenticity, as well as to inconspicuously send data to a specific destination. “Already there are several companies using DNA to tag objects that they certify to be original and which then can be very difficult to counterfeit,” says Stefano Lonardi, Associate Professor of Computer Science & Engineering at UCR’s Bourns College of Engineering.

For example, the British company, Redweb Security, has developed something called i-powder that tags DNA and another company called PSA DNA Authentication services tags sports memorabilia.

“What we developed at UCR is a method to encode a message in DNA in a way that does not require an expensive sequencing machine,” notes Lonardi. “The decoding still requires a wet lab procedure, but the experimental procedure is significantly easier.”

The article, entitled “Length-based Encoding of Binary Data in DNA,” was published by the American Chemical Society in Langmuir December 18, 2007.

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