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POPSPalin and the fruit fly or just plain ignorance
One might have thought that Sarah Palin would take a more active interest in one aspect of scientific research. Palin's youngest son has Down's syndrome, a genetic disorder caused by the presence of an extra chromosome 21. Although a geneticist by training, I am certainly no expert on the pathogenesis of this condition, nor the significance of Drosophila research into Down's syndrome. So, I typed "drosophila trisomy 21" into PubMed, the scholarly biomedical equivalent of Google. There were 109 results, the most recent published just the day before Palin's gaffe. The concluding sentence of that study — about the genetic cues that steer nerve fibres around during the growth of the fruit fly — suggests that the paper will "have implications for the pathogenesis of Down's syndrome". These two are drops in the ocean of fruit fly research that have clinical relevance. Down's syndrome, Alzheimer's disease, autism, diabetes, ageing research, cancers of all types
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POPSWhat is a gene? gene - A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Genes undergo mutation when their DNA sequence changes. (Answers)
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POPSExploding chromosomes fuel research about evolution of genetic storage
Dinoflagellates are stuffed at the core with tightly compacted chromosomes, yet these organisms contain neither histones nor nucleosomes. "What takes care of neutralizing DNA, to allow chromosomes to condense?" Levi-Setti asked. "Most biology books do not tell you." Other scientists had already identified positively charged atoms called cations as neutralizing factors. They found that dinoflagellate chromosomes explode upon the removal of calcium and magnesium cations. Levi-Setti has produced the first images of the distribution of these cations in dinoflagellate chromosomes. These images verify that cations, mainly of calcium and magnesium, neutralize DNA's enormous negative charge, and further suggest a critical role in folding the protein as well. The finding raises questions about the evolution of chromosomes, Rizzo said. "Did dinoflagellates once have histones and then lost them? Or did dinoflagellates never have histones and just 'figured out' a different way to fold lar
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POPSGenetics Show How Prehistoric Cultures Migrated & Shared Knowledge The researchers tracked genetic variation on the Y chromosome, the sex chromosome passed from father to son that encodes maleness, using a technique now widely used that was developed in the early 1990s by Underhill and colleagues in the lab of Luigi Cavalli-Sforza, professor emeritus of genetics. The method has given scientists a powerful window into ancient human migrations and prehistoric cultural shifts. The technique has also been adopted by some commercial genealogy services that offer Y-chromosome testing to the public.
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POPSAre You REALLY A Woman? "The tests never unmasked a man posing as a woman, but they did turn up several athletes who were born with genetic defects that made them appear — according to lab results, at least — to be men. In 1967, the Polish sprinter Ewa Klobukowska was barred from the sport because she failed the chromosomal test, even though she had passed the nude test a year earlier. In the 1980s, the Spanish hurdler Maria José Martínez Patino was disqualified because the test revealed, to her surprise, that she was born with a Y chromosome. Her eligibility was reinstated in 1988. The practice came under increasing criticism in the 1990s by doctors, scientists and athletes who argued that the tests were not just invasive, but were also bad science."
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POPSSmoking and the smoking gene another report has drawn rather different conclusions... that genetic variation there acts directly on a person's susceptibility to lung cancer, rather than acting indirectly by modifying his smoking behaviour. That does not mean the gene or genes in question actually cause lung cancer. Rather, it means that they amplify the effects of smoking instead of the amount of smoking.
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POPSWhy some smokers don't get Lung Cancer Yes, I am a smoker. And after reading this news article, It still doesn't change my mind about quiting smoking. I need to quit! For my health and the heath of the people around me. And also the fact that I can save a lot of money each week from not buying cigarettes. Even if I were one of the select few that don't get Lung Cancer, that still means nothing to me, and it shouldn't mean anything to other smokers out there either. Because a lot more things can happen to a smoker, than just Lung Cancer.
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POPSGenetics Revolution Continues DAWKINS: It’s more than just saying you can pick up a chromosome and put it in somewhere else. It is pure information. You could put it into a printed book. You could send it over the Internet. You could store it on a magnetic disk for a thousand years, and then in a thousand years’ time, with the technology that they’ll have then, it would be possible to reconstruct whatever living organism was here now. What has happened is that genetics has become a branch of information technology. It is pure information; it’s digital information; it’s precisely the kind of information that can be translated digit-for-digit, byte-for-byte into any other kind of information.
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POPSSynthetic life - a step nearer Moreover, Dr. Venter’s team, led by a Nobel laureate, Hamilton O. Smith, has yet to accomplish the next — and biggest — step. That would be to insert the synthetic chromosome into a living microbe and have it “boot up” and take control of the organism’s functions. If that happened, it would be considered by some to be the creation of the first synthetic organism. The failure to achieve that tempered the reaction of some outside scientists to the announced achievement. “Right now, all they’ve done is shown they can buy a bunch of DNA and put it together,” said George M. Church, a professor of genetics at Harvard Medical School. Dr. Venter’s team last year reported successfully doing such a chromosome transplant, but it was with the natural genome of one type of Mycoplasma transplanted into another species of that bacterium. (NYT)
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POPSGene map for synthetic life created in lab The Bacterium, M. genitalium has the smallest known genome of any truly living organism, with 485 working genes all in one chromosome. Viruses are smaller, but they cannot replicate by themselves. Dr Craig Ventner is described as a celebrity scientist. Struck me as an unusual way to describe a scientist.
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POPSThe end of Men? A surprising number of animals can reproduce without male involvement if there is no other option. Sharks and lizards have demonstrated this ability in captivity. It was previously believed that the process was impossible in mammals such as humans because male sperm cells and female egg cells undergo a process called imprinting. In imprinting, sections of each cell’s genome are silenced to allow the set of genes from the other parent to be expressed, so that when the egg and sperm cells combine, the genes in the resulting embryo are not competing with each other. It has now been discovered that it is possible to interrupt this process by deleting just two sections of genetic material on the genomes of female mice – animals very similar, for reproductive purposes, to humans.
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