Science News Digest – 10th October 2012
In the science news this week, mice bred from eggs created from stem cells, the world’s most northerly lake comes back to life, mammoth carcass found in Siberia, and finally… a free font that helps dyslexics to read online.
Mice created from stem cells
Scientists have created mouse eggs from stem cells and fertilised them to make healthy baby mice for the first time.
The team from Kyoto University in Japan took stem cells from mice and genetically reprogrammed them to develop into egg precursor cells, which when mixed with body cells from female mice and implanted into the mice developed into mature eggs.
These eggs were then successfully fertilised in the lab using IVF and the resulting pups were healthy and fertile.
This technique has been used before, in 2003, when researchers from the University of Pennsylvania created mice eggs from stem cells, but they did not use them to create mouse pups.
The authors suggest that the technique could be used as a treatment for infertile women, to develop viable eggs for fertilisation and implantation.
"Our system serves as a robust foundation to investigate and further reconstitute female germline development in vitro, not only in mice, but also in other mammals, including humans," wrote the authors in Science.
The team used two types of stem cells: embryonic stem cells, which are found in early-stage embryos and have the ability to develop into any type of tissue in the body; and induced pluripotent stem cells, which are reprogrammed cells taken from an adult.
The Guardian reported that the technique, although successful, was also highly inefficient, with just five pups being born from 127 implanted embryos (3.9%) compared to the control group, which used normal mouse reproductive cells, and showed a success rate of 13 pups being born out of 75 implanted embryos (17.3%).
Dr Allan Pacey, a fertility expert from the University of Sheffield and chair of the British Fertility Society, told the Guardian that although this was a promising study, there was still a long way to go before this could be considered a treatment in humans.
"This is a very technical piece of work which pushes much further the science of how eggs are generated and how we might one day be able to routinely stimulate the new production of eggs for women who are infertile.
"What is remarkable about this work is the fact that although the process is still quite inefficient, the offspring appeared healthy and are themselves fertile as adults. This is a great step forward, but I would urge caution as this is a laboratory study and we are still quite a long way from clinical trials taking place in humans."
The world’s most northerly lake shows signs of life
Kaffeklubben Sø, located on the coastal plain of northern Greenland at 83o 37’ north, has been emtombed beneath a near-permanent layer of ice for 2,400 years. Now, the lake is showing signs of thawing, and some of the organisms are beginning return to the waters, reported New Scientist.
The lake is covered by about one to two metres of ice all year round, but during the summer a ‘moat’ of water forms around the edge of the lake when temperatures reach about 1.6oC.
The lake formed about 3,500 years ago, and a few species of silica-shelled algae called diatoms lived in the newly formed lake. But their numbers declined as the temperatures dropped until they eventually vanished about 2,400 years ago. Some cyanobacteria managed to survive below the ice as they require little light.
The lake remained almost entirely barren until around 1960 when the first diatom species returned to the waters. In the latest samples, Bianca Perren from the University of Franche-Comte in France and her colleagues, found 20 species.
This is not the only lake to show these changes, however. Last year, Alex Wolfe from the University of Alberta in Canada and colleagues, reported that nitrates and industrial pollutants may have encouraged diatoms to bloom in other lakes.
However, there aren’t any traces of nitrates in Kaffeklubben, which suggests the bloom was purely driven by the warming of the lake.
Remains of a mammoth found in northern Siberia
An 11-year-old boy from northern Siberia has discovered the remains of an adult mammoth whilst out walking his dogs, reported the BBC. The carcass was found in August in Sopochnaya Karga, 2,200 miles northeast of Moscow and was extracted from the frozen mud by a team from St Petersburg.
The excavation took five days of careful work, explained Sergei Gorbunov, from the International Mammoth Committee.
"We had to use both traditional instruments such as axes, picks, and shovels as well as such devices as this "steamer" which allowed us to thaw a thin layer of permafrost.
"Then we cleaned it off, and then we melted more of it. It took us a week to complete this task."
The mammoth is estimated to have been 16 years old when it dies, standing at 2m tall and weighing about 500kg. It has been incredibly well preserved by the frozen mud that was surrounding it, and it has been named, Zhenya, after Zhenya Salinder, the young boy who made the discovery earlier this year.
New font that helps people with dyslexia to read online
A free font has been gaining favour, according to the BBC, and is now being offered by different apps and software companies as an option for their users.
The font works by having characters with “heavily weighted bottoms” to stop them appearing to flip and swap around in the minds of the readers.
"I had seen similar fonts, but at the time they were completely unaffordable and so impractical as far as costs go," said Abelardo Gonzalez, who developed the font.
"I figured there's other people who would like the same thing but had the same issues, and so I thought I'd make an open source one that everyone could contribute to and help out with.
"The response has been great: I've had people emailing saying this is the first time they could read text without it looking wiggly or has helped other symptoms of dyslexia."