the-BA : Science News Digest

Unhappiness is most common among 40-50 year olds (image copyright: istockphoto.com)

In the science news this week: sperm cells created from female stem cells, a memory restoration breakthrough and the ancestor that turned brown eyes blue. Plus, a worldwide happiness study reveals the misery of middle-age...

UK scientists have reportedly coaxed female embryonic stem cells into developing into primitive sperm cells. The work raises the possibility that it could one day be possible for lesbian couples to have their own biological children.

However, for these cells to be able to undergo fertilisation, they would first have to undergo a process called meiosis so that the right amount of DNA would be present. The University of Newcastle group are now applying for permission to use female bone marrow stem cells, as this would make the method more practical.

Whether it is actually possible to produce functional sperm cells from female cells is questioned by some scientists since only men possess the Y chromosome that carries several genes thought to be essential to make sperm.
(Read more in the Telegraph)
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There are many hypotheses for how life began on Earth. Some suggest the key ingredients originated in outer space, while most have more Earth-bound explanations. This week, the Telegraph reported new evidence published in the journal Science that places hydrothermal vents on the sea floor as even stronger contenders for the sites where life originated on Earth.

The temperature and fluid composition at these hot underwater springs are similar to those predicted to have occurred when life was beginning, and now a team has reported that hydrocarbons – chemical molecules critical for life – are routinely being generated at the Lost City, one of these sites in the mid-Atlantic. They are being produced by simple chemical reactions between seawater and the underlying rocks.

’The generation of hydrocarbons was the very first step, otherwise Earth would have remained lifeless,’ said Dr Giora Proskurowski, one of the paper’s authors. ‘The detection of these organic building blocks from a non-biological source is possible evidence in our quest to understand the origin of life on this planet and other solar bodies.’
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More than 99.5 per cent of blue-eyed people analysed in a study share the same tiny mutation, suggesting that the mutation originated in one person, changing the eye colour from the ‘default’ brown, and that this person became their common ancestor. About 800 people, ranging from fair-skinned, blond-haired Scandinavians with blue eyes, to dark-skinned, blue-eyed people living in Turkey and Jordan, had their DNA analysed.

Professor Hans Eiberg and colleagues at the University of Copenhagen found that all apart from possibly one exception had exactly the same DNA sequence in the region of the OCA2 gene. This created a ‘switch’ that literally turned off the ability to produce brown eyes.

Other evidence, reports the Independent, suggests that the mutation probably arose about 10,000 years ago when the spread of agriculture from the Middle East resulted in a rapid expansion of the human population in Europe. The reason for the spread of blue eyes among northern European and southern Russian populations is unknown, but it may be that the colour either offered some advantage to long daylight hours in summer, or to short daylight hours in winter, or that it was advantageous in terms of sexual selection because it was deemed attractive.
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I hope you’re not as suggestible as I am, otherwise this next news item about itching will have you scratching your arms until they bleed. But why is it that, even if you take it that far, scratching can be so pleasurable? Well, according to a study in which 13 volunteers alternated between scratching and not while their brains were monitored by magnetic resonance imaging (MRI), the action suppresses activity in areas of the brain associated with unpleasant memories and emotions.
(The Times)
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Scientists made an accidental discovery that may allow them to unlock memories and could possibly help Alzheimer sufferers. They were using deep-brain stimulation (where electrodes are inserted into the brain and stimulated with electric current) as a method to suppress an obese man’s appetite. But instead of losing his appetite, he strongly recalled a memory from 30 years earlier.

They also found that continuous hypothalamic stimulation improved the man’s ability to learn lists of paired objects and he was also much more likely to remember a list of unrelated paired objects when the electrodes were stimulating his brain.

The researchers are now testing the method in a Phase 1 safety study on Alzheimer patients. If the method works, it is hoped it could provide a ‘pacemaker’ for the brain.
(Read more in the Independent)
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We could one day be sticking out our tongues to receive vaccinations against a wide range of viruses, rather than having to endure a needle, if new research in mice translates to humans. Scientists from the International Vaccine Institute in Seoul have demonstrated that the sublingual method, where a solution of vaccine is delivered to the floor of the mouth, is highly effective in protecting mice against influenza virus infection.

‘These studies provide a basis for further human testing of this alternative form of needle-free vaccination. Aside from its convenience, sublingual vaccination appears to disseminate immunity to a broader range of organs than the classical routes of injecting or ingesting vaccines,’ says Dr Cecil Czerkinsky, International Vaccine Institute Deputy Director-General for Laboratory Science.

‘If these findings are replicated in humans, they could pave the way for the development of a new generation of vaccines that could be used for mass vaccination against enteric, genital, and respiratory infections, including the pandemic avian-human influenza viruses.’
(Read more in the Telegraph)
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Other news in brief:

A new species, the biggest yet, of giant elephant-shrew has been discovered in the mountains of East Africa. There are only three other known species of the animal and this is the first new discovery in over 125 years. More closely related to elephants, aardvarks and sea cows than to shrews, they are known as living fossils because their body shape has remained virtually unchanged for up to 23 million years.
(The Times)
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The common belief that chameleons evolved their impressive ability to change colour in order to blend in to their surroundings is apparently wrong – new research suggests that the ability developed to enable them to rapidly signal to other chameleons, to impress rivals and members of the opposite sex.
(The Telegraph)
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The secret of starlings' ability to fly in huge flocks, twisting and turning with Red Arrow precision, has been revealed: they track seven other birds. By monitoring this fixed number of neighbours, irrespective of distance apart they are able to remain very cohesive, and even if they come under attack they are able to regroup rapidly so that individuals aren’t left isolated and at risk from a bird of prey. The results could help in the field of mobile robotics.
(The Telegraph)
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A new class of drug to treat HIV was introduced in Britain this week. It works by blocking the enzyme that HIV relies on to replicate itself and has been approved for use with other antiretroviral drugs in cases where the existing therapy has stopped working. Three quarters of patients involved in the drug trial showed a significant reduction in viral load – and in some cases the improvement was so great that levels of the virus were undetectable in the blood.
(The Times)
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Scientists have discovered an enzyme that controls the rate of ovulation, by preventing immature eggs from ripening prematurely. Mice lacking PTEN in their eggs use up their store of eggs more rapidly as the entire pool of immature eggs is activated prematurely. The researchers now intend to investigate whether mutations in the PTEN gene could be linked to premature menopause in woman.
(The Telegraph)
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And finally...

A worldwide study involving more than two million people from 80 countries has shown that we are happiest towards the beginning and ends of our lives, and most likely to become depressed between 40 and 50.

In a pattern that was strikingly consistent in the vast majority of countries looked at, people’s levels of happiness followed a U-shaped curve. The Guardian reported that, in the UK, the probability of becoming depressed peaked at age 44 for both men and women.

’Some people suffer more than others but in our data the average effect is large,’ said Andrew Oswald, from the University of Warwick. He thinks that realising feelings of unhappiness are completely normal in mid-life might help individuals survive this phase better.

‘What causes this apparently U-shaped curve, and its similar shape in different parts of the developed and even often developing world, is unknown. However, one possibility is that individuals learn to adapt to their strengths and weaknesses, and in mid-life quell their infeasible aspirations. Another possibility is that cheerful people live systematically longer.’

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