Press releases
Please quote Nature Biotechnology as the source of these items.
The July 2007 issue of Nature Biotechnology is available online.
July 2007
International collaboration surveys human embryonic stem cell lines
The first comparative study of a large number of human embryonic stem (hES) cell lines is reported online this week in Nature Biotechnology. Conducted by the International Stem Cell Initiative (ISCI), the study examines 59 hES cell lines from 17 laboratories in the United States, Europe, Israel, Japan and Australia. Although the 59 lines were derived using different methods from embryos with diverse genotypes, they proved very similar with regard to the expression of genes and proteins commonly used to identify hES cells.
Many laboratories around the world work with hES cell lines using various experimental techniques, and scientists do not understand the extent of the similarities and differences among the lines. As this technology moves closer to clinical application, it will be important to develop more standardized and reproducible methods for deriving, culturing and characterizing hES cells. The ISCI is seeking to address this challenge through an international collaboration of unprecedented scale. The present report covers the first phase of their ongoing effort.
Characterization of human embryonic stem cell lines by the International Stem Cell Initiative pp 803 - 816
The International Stem Cell Initiative
Published online: 17 June 2007 | doi 10.1038/nbt1318
Genetic engineering boosts biofuel yield from alfalfa
Transgenic alfalfa containing less lignin than conventional alfalfa is a better crop for ethanol production, according to a report published online this week in Nature Biotechnology. The study shows that alfalfa engineered to be defective in biosynthesis of lignin - the substance that strengthens plant stems and woody tissue ? is more susceptible to digestion by the enzymes used to convert plant material into sugars from which bioethanol is produced.
One problem that researchers face in extending bioethanol production is the difficulty of solubilizing the fermentable sugars in crops such as poplar and switchgrass. As most of the plant material available for bioenergy contains lignin, it must first be treated with acid at high temperatures to expose the plant cell walls before their digestion into sugars that are subsequently fermented into bioethanol.
Fang Chen and Richard Dixon show that various transgenic lines of the forage legume alfalfa can be engineered with antisense molecules. These molecules interfere with the RNAs that encode certain key enzymes involved in the biosynthesis of lignin and produce much more sugar for fermentation into bioethanol. The advance opens the way to exploit biofuel feedstock from plants not suitable for food production, or material like corn stover that might otherwise be discarded.
As some of the transgenic alfalfa stems yield almost double the amount of sugar released from conventional alfalfa, the approach promises to reduce the costs and increase the yield of bioethanol production from alfalfa as well as reduce the need for environmentally damaging acid in the biofuel refining process.
Lignin modification improves fermentable sugar yields for biofuel production pp 759 - 761
Fang Chen & Richard A Dixon
Published online: 17 June 2007 | doi 10.1038/nbt1316