Experts in ancient DNA from McMaster University (Canada) have teamed up with genome researchers from Penn State University (USA) for the investigation of permafrost bone samples from Siberia. The project also involved paleontologists from the American Museum of Natural History (USA) and researchers from Russia, the United Kingdom, France, and Germany. The researchers report on the first genomic sequences from a woolly mammoth will be published on 22 December 2005 by the journal Science on the Science Express website. This majestic mammal roamed grassy plains of the Northern Hemisphere until it became extinct about 10,000 years ago. The scientific breakthrough allows for the first time comparion of this ancient species with todays populations of African and Indian elephants, not just at the level of mitochondrial sequences, but also encompassing information from the nuclear genome.
Analyzing organellar DNA from mitochondria has been the only method of studying ancient DNA in the past, as it is more tractable due to its 1000-fold higher copy number per cell. However, the mitochondrial genome codes for only a tiny fraction of an organisms genetic information -- 0.0006 percent in the case of a mammal. In contrast, most hereditary information is organized on chromosomes located in the cells nucleus (nuclear DNA). A mammoth was chosen for study in part because of its close evolutionary relationship to the African elephant, whose nuclear DNA sequence has been made publicly available by the Broad Institute in Cambridge, Massachusetts (USA). Using comparisons with elephant DNA, the researchers identified 13 million base pairs as being nuclear DNA from the mammoth, which they showed to be 98.5 percent identical to nuclear DNA from an African elephant.
The project became possible through the discovery of exceptionally well preserved remains of a mammoth skeleton in the permafrost soil of northern Siberia, in combination with a novel high-throughput sequencing technique that could cope with the heavily fragmented DNA retrieved from the organisms mandible, its jaws. The bone material used in this study is approximately 28,000 years old, as was shown by beta-carbon dating analysis. This was a surprising finding, as it demonstrated that the analyzed material was frozen for more than 10,000 years before the maximum of the last ice age. The research team used a computational approach to demonstrate that an unprecedented 50 perecent of the bone DNA was indeed mammoth DNA, while the remaining genetic material was shown to belong to microorganisms living the tundra soil.
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07.12.2016 | National Centre for Biological Sciences
Transforming plant cells from generalists to specialists
07.12.2016 | Duke University
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
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07.12.2016 | Health and Medicine