July research blog : Bird genetics and a massive magnet

Birds are the perfect vehicle for learning more about genetic evolution

The Bird is the Genetic Word
There are lots of birds on earth, and so far over 10,500 different species have been identified. This large family is now going to be comprehensively catalogued in a new project by the Danish Center for Macroecology, Evolution and Climate and the University of Copenhageny, together with partners in China and the US. The Bird 10,000 Genomes Project, or B10K for short, is a five-year endeavour to sequence every single living avian species. We will learn in greater detail not only about the subtleties of each species, but also how they are related to each other through evolution.

The catalyst for the project came in 2010, when Guojie Zheng and Thomas Gilbert – both from the University of Copenhagen – were trying to sequence the pigeon genome, but could not find its closest relative. At the time, the complete genomes of only three bird species had been sequenced – the chicken, turkey and zebra finch. They realized that there was too little data to go on.

Birds are the perfect vehicle for learning more about genetic evolution. Their sheer number of species and dispersion around the world make them a perfect model for studying population genetics, neurobiology, development, migration habits and animal conservation. Combine that with our penchant for using birds as food and the impacts they are having on our health – bird flu and West Nile virus come to mind – and the importance of understanding our feathered friends becomes clear.

When finished, the B10K will be a tree of life for the entire living avian class on the genomic level. It will shed light on the correlation between evolution and geographical location, showing us how an organism’s environment affects the way it develops. Furthermore, we may gain insight into how different organisms affect each other’s development and dispersion around the world. At the very least, it will leave us better prepared in case we ever find ourselves in a real-life version of Hitchcock’s The Birds.

One Magnanimous Magnet
Some say that size doesn’t matter. The University of Aarhus wouldn’t agree. The institution now boasts the largest magnet in Northern Europe. But fear not – they are using their power for good.

The University’s new Nuclear Magnetic Resonance spectrometer (NMR) allows researchers to magnify all the way down to the atomic scale. Two to three times more sensitive than previous NMR microscopes, it will help researchers focus more sharply on the smallest building blocks in the body, such as cells, proteins, and molecules.

The researchers initially hope to use it to further the field of antibiotics. Since the advent of penicillin, we have been fighting a losing battle against bacteria. Those little guys have been learning, evolving and growing in a way that resists antibiotic treatment.

Penicillin and other antibodies work by entering bacterial cells and changing how some of their proteins work. Essentially, penicillin has the difficult task of going into enemy territory and making the troops march in a different direction. While this has been working effectively for some time, it is clear that the opposition has started understanding the strategy and is adapting to it. Increasing numbers of bacterial strains are becoming antibiotic-resistant, posing some serious health problems.

Researchers at the Interdisciplinary Nanoscience Centre (iNANO) are now using the NMR to monitor a new antibiotic strategy using antimicrobial peptides (AMPs). These molecules attack the cell membrane, which is essentially a layer of fat that acts as a rubber band that holds the rest of the cell together. When the membrane is damaged, the cell dies.

The membrane cannot mutate, so it is believed that bacteria cannot become resistant to AMPs in the same way that they become resistant to other antibiotics. AMPs are already found in the immune systems of many classes of life, such as fungi, plants and snails.

But while AMPs show promise, there are some potential drawbacks. Some bacteria have natural systems in place to fight off AMPs, for example by switching the charge of the membrane, or by acting as though they have already been attacked by AMPs. AMPs are also digested in the stomach, and cannot be used to specifically attack certain types of bacteria.

Still, they hold a lot of promise, and researchers at Aarhus University and iNANO hope to use the colossal NMR to see in even more detail how AMPs work and interact with bacteria.

“I believe in AMPs because their modes of action are so simple. They just destroy the cell. Working with them isn’t simple, but the effect is,” says Professor Vosegaard, head of AMP research at iNANO. “But we’re very focused on the fact that we need quite a bit more knowledge about AMPs. We’ll eventually use this knowledge to design some new substances that can be used for medicine.”


By Nereya Otieno

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