Science News Digest - 18 December 2012
A special seasonal edition of the Science News Digest looks at some of the festive stories in the news this week. Scientists trying to crack the Christmas tree genome share their progress, we look at the impact of the poor summer weather on Christmas crops, and we finally find out why Rudolph’s nose is red! The digest will return early in the New Year, until then, the British Science Association would like to wish everyone a very happy Christmas, and a science-filled 2013.
Cracking the Christmas code…
Whilst for some, it’s a cheerful sight that epitomises the festive season, for the scientists across the world trying to sequence its genome, the Christmas tree may induce very different emotions. This mammoth task is being dealt with by teams around the world, but has proved to be no easy ride. The Norway spruce, a firm favourite from amongst the conifers, has a genome six time longer than a humans. It is only estimated to have 35,000-40,000 genes however, compared to 23,000 in humans – the difference in length can be accounted for by the large amounts of non-gene DNA, bulking out the genome.
After recent preliminary sequences were releases earlier this year in the US and Canada, a Swedish team is making advances in its work to describe the entire Norway spruce Genome.
"Until just a few years ago, the idea of sequencing even a single conifer genome seemed impossible," said John MacKay of the University of Laval in Quebec City, speaking to the Guardian who co-directs a multi-institution Canadian project working on the white spruce. The new technologies changed that, he said.
Although the process of sequencing small sections of DNA has become much quicker and cheaper in recent years, the task of re-assembling these sections back in to the long DNA sequences is still an extremely challenging task in conifers, as their sequences contain so much repetition.
The scientists believe that uncovering the genetic code will have many-fold benefits, including allowing breeders to selectively breed trees with the most desirable qualities .(our staff rated a tree which never lost its needles, no matter how much your cat jumped on it, as the most desirable property a tree could have.) Further to this though, it may allow forest managers to select the best varieties to plant to adapt to climate change in coming decades.
As for the Swedish project on Norway spruce, Par Ingvarsson of Umea University in Sweden, who is leading the Norway spruce project. said its results will be made public early next year. The 2 million DNA pieces have captured most of the estimated 35,000 to 40,000 genes in the tree, even if researchers don't know yet, where those genes go in the overall genome sequence.
Summer storms and small sprouts…
After a distinctly underwhelming summer, weather-wise, it may not come as a surprise that Britain’s crops have suffered from the effects of excess rainfall. The BBC offer an explanation as to why some Christmas staples have suffered so much, and why shoppers may feel the effect.
Potatoes farmers have had a tough year. Despite the drought that started the growing season, 2012 later proved to have the wettest summer for 100 years. The waterlogged ground leads to poor growing conditions, smaller potatoes, and more difficult conditions for picking and ploughing. Another favoured root vegetable, the carrot, has suffered a similar fate, and Office of National Statistics (ONS) November figures suggest that prices have risen by 43% and 44% respectively for these two crops, in the last 12 months.
Meat products have also suffered – both turkey and pig farmers have seen feed prices rise dramatically. Soya and wheat jumped in price after the USA, South America, Russia and the Black Sea states suffered their worst drought in decades. The high rainfall meant that UK-grown wheat did not fare any better. 60% of the cost of raising a turkey is made up of food costs, so turkey steak and wholesale prices have increased in the last 12 months. Pork prices have also been pushed up as EU farmers cut their herds, ahead of new welfare regulations in January.
News that the humble Brussels sprout has also suffered considerably, will perhaps not come as a blow to many. Brassica growers however, have spent a difficult year, contending with waterlogged soil in July and August, which hindered root development. The Christmas period accounts for a third of annual sprout sales, so growers now face a battle to harvest enough to meet demands. Luckily, supermarkets have widened the range of sprouts they are willing to buy, to help British farmers make the most of their crops, so don’t be surprised if your sprouts are a little bit smaller this year!
Won’t you guide my sleigh tonight?
Scientists may finally have answered an age-old Christmas mystery – just what makes Rudolph’s nose glow so brightly red?
Experts from Erasmus University Rotterdam have proposed a new theory to answer this pressing question – suggesting that Rudolph’s nose is red because it is richly supplied with red blood cells which help to protect it from freezing and to regulate brain temperature.
This superior “nasal microcirculation” is essential for pulling Santa Claus’s sleigh under extreme temperatures, reveals a study in the Christmas issue of the BMJ.
The tiny blood vessels in the nose are vital for delivering oxygen, controlling inflammation, and regulating temperature, although few studies have assessed their function in detail.
Knowing how important this regulation is for flying reindeer, who have to deal with extremes of temperature while pulling a sleigh, researchers set out to test whether Rudolph’s infamous red nose was due to “a highly dense and rich nasal microcirculation” compared with human noses.
The researchers used a hand-held video microscope, to assess the noses of five healthy human volunteers. They found a circulating blood vessel density of 15 mm/mm2, whereas tests on reindeer noses showed a 25% higher density of blood vessels, carrying a super-rich concentration of red blood cells.
“The microcirculation of the nasal mucosa in reindeer is richly vascularised and 25% denser than that in humans,” say the authors. “These factors explain why the nose of Rudolph, the lead flying reindeer employed by Santa Claus to pull his sleigh, is red and well adapted to carrying out his duties in extreme temperatures.”