Genetics

From Robby Berman at BigThink: While it’s true that every chromosome contains some of 25,000 genes, it now turns out to be the case that this is only a little more than half the story. Computer modeling has revealed that up to 47% of each chromosome is an enigmatic sheath-like substance called the “chromosome periphery,” something about which little is known. That’s because it’s almost impossible to get a good look at in actual chromosomes. … It looks like chromatin do make up from 53% to 70% of chromosomes, but the rests is the mysterious chromosome periphery. Earlier research by Booth suggests that the chromosome periphery requires the presence of the protein Ki-67 that’s believed to act as a surfactant Read More ›

From ScienceDaily: Our current understanding is that mice have either no — or extremely limited — neural circuitry and genes similar to those that regulate human speech. According to a recent study published in Frontiers in Behavioral Neuroscience, this understanding may be incorrect. … Dr. Jarvis and colleagues report the results of their investigation into the effect of a genetic mutation in the Forkhead box protein #2 (FOXP2) on the vocalization patterns of adult male mice. FOXP2 regulates speech production in humans. Individuals with deficiencies in FOXP2 protein have difficulty forming complex syllables and complex sentence construction. Although mice are unable to communicate using speech in the same way as humans, they do vocalize as a means of communicating with Read More ›

From ScienceDaily: Nature is full of parasites — organisms that flourish and proliferate at the expense of another species. Surprisingly, these same competing roles of parasite and host can be found in the microscopic molecular world of the cell. A new study by two Illinois researchers has demonstrated that dynamic elements within the human genome interact with each other in a way that strongly resembles the patterns seen in populations of predators and prey. … Goldenfeld and Xue embarked on this work because of their interest in transposons, small regions of DNA that can move themselves from one part of the genome to another during the lifetime of a cell — a capability that has earned them the name “jumping Read More ›

From comparative medicine specialist Joseph Garner, interviewed by Aviva Garner at New Scientist: Of the drugs that get past the animal testing phase and into human trials, only about 1 in 9 actually make it to the market, and that’s dropping all the time. It costs about $2 billion to bring a single drug to market, largely because of failed human trials. And they usually fail simply because the drug doesn’t work, or not as well as animal testing predicted. (most paywalled) More. It may be relevant that humans can think, say, and do a lot of things that mice cannot, and we are not kept in cages all our lives either. So a disease would run its course in Read More ›

From ScienceDaily: For the first time, scientists have revealed ancient gene mixing between chimpanzees and bonobos, humankind’s closest relatives, showing parallels with Neanderthal mixing in human ancestry. The study showed that one percent of chimpanzee genomes are derived from bonobos. Only one percent? Keep the file open. Paper. (public access) – Marc de Manuel et al. Chimpanzee genomic diversity reveals ancient admixture with bonobos. Science, 2016; 354 (6311): 477-481 DOI: 10.1126/science.aag2602 … Chimpanzees and bonobos are the closest living relatives of human beings. They diverged from a common ancestor between 1.5 and 2 million years ago and live in different areas of tropical Africa. Until now, it was thought that gene flow between the species would have been impossible, as Read More ›

From ScienceDaily: Millions of years ago, one species of frog diverged into two species. Millions of years later, the two frogs became one again, but with a few extra chromosomes due to whole genome duplication. Such is the curious case of the African clawed frog, Xenopus laevis, a frog whose genome contains nearly double the number of chromosomes as the related Western clawed frog, Xenopus tropical is. In the evolution of species, different events have occurred over millions of years that have increased the number of chromosomes in some organisms. Polyploidy describes an event that increases the number of copies of each chromosome. Vertebrates have undergone at least two different polyploidy events since their original divergence. While it is relatively Read More ›

Further to Rethinking the links between genes and disease, from Erica Check Hayden at Nature: Many disease-association studies, particularly in recent years, have identified mutations as pathogenic simply because scientists performing analyses on a group of people with a disorder found mutations that looked like the culprit, but didn’t see them in healthy people. But it’s possible that they weren’t looking hard enough, or in the right populations. Baseline ‘healthy’ genetic data has tended to come mainly from people of European descent, which can skew results. … In August this year, MacArthur’s group published its analysis of ExAC data in Nature, revealing that many mutations thought to be harmful are probably not. In one analysis, the group identified 192 variants Read More ›

Because many mutations are benign. From an editorial at Nature: One of the major findings of the Exome Aggregation Consortium (ExAC), the largest-ever catalogue of genetic variation in the protein-coding regions of the human genome, is that many genetic mutations have been misclassified as harmful (M. Lek et al. Nature 536, 285–291; 2016). Authors of that study estimate that each person has lurking in their genome an average of 54 mutations that are currently considered pathogenic — but that about 41 of these occur so frequently in the human population that they aren’t in fact likely to cause severe disease. That finding is having major consequences for some people with such variants, lifting the equivalent of genetic death sentences. More. Read More ›

From Douglas Axe’s Undeniable, Consider popular wisdom about genes and DNA. Just as most peole think scientists havefigured out how the brain works, so too they think scientists have figured out how DNA works. By my casual observation, most nonscientists—and some scientists as well—think the blueprint from which every living organism was formed is written on that individual’s genome in the language of genes. Accordingly, geese honk because they have the honk gene, and hyperactive dogs yap because they have the hyperactive-dog gene. Likewise, by this popular view people who can sing or whistle received these abilities by receiving the corresponding genes. The master template for specifying all our attributes became public with the publishing of the human genome, supposedly, Read More ›

From a study of the impossibly ugly tomato hornworm: Eurekalert: Comparing the moth’s genes and genome to those from other insects revealed an intriguing peculiarity: “In many insects we know that genes often jump around from one location to another in their respective genomes”, described Dr Robert Waterhouse from the SIB Swiss Institute of Bioinformatics and the University of Geneva, “but in moths and butterflies something seems to be reducing their freedom of movement”. Prof. Marian Goldsmith from the University of Rhode Island explained that “This exceptional conservation of gene order may be linked to the special structural properties of moth and butterfly chromosomes.” More. Free artsie education for nerds: A number of poems have been written about how ugly Read More ›

A new study could explain why DNA and not RNA, its older chemical cousin, is the main repository of genetic information. The DNA double helix is a more forgiving molecule that can contort itself into different shapes to absorb chemical damage to the basic building blocks — A, G, C and T — of genetic code. In contrast, when RNA is in the form of a double helix it is so rigid and unyielding that rather than accommodating damaged bases, it falls apart completely. … “For something as fundamental as the double helix, it is amazing that we are discovering these basic properties so late in the game,” said Al-Hashimi. “We need to continue to zoom in to obtain a Read More ›

Amazing protein diversity in maize From Eurekalert: Cold Spring Harbor, NY — The genome of the corn plant – or maize, as it’s called almost everywhere except the US – “is a lot more exciting” than scientists have previously believed. So says the lead scientist in a new effort to analyze and annotate the depth of the plant’s genetic resources. “Our new research establishes the amazing diversity of maize, even beyond what we already knew was there,” says Doreen Ware, Ph.D., of the US Department of Agriculture and Cold Spring Harbor Laboratory (CSHL) in New York. “This diversity is fascinating in its own right and at the same time has great import for agriculture.” Maize is one of the world’s Read More ›

Yes, it sounds weird. By the way, sell your stock in Dawkins’ selfish gene. Anyway, listen: From Science Alert: Hundreds of genes spring to life up to 4 days after death, scientists find A pair of papers published this week discuss evidence that certain parts of the body are still firing even days the rest have stopped functioning, and it could change the way we think about organ transplants and time of death. Led by microbiologist Peter Noble, a team from the University of Washington has been investigating the gene activity in deceased mice and zebrafish, prompted by previous research that identified a handful of genes in human cadavers that were active more than 12 hours after death. The researchers Read More ›

From Emily Singer at Quanta: According to the new findings, published in Genetics this month, Neanderthal genomes were rife with harmful DNA that significantly reduced the species’ fitness. The researchers conclude that Neanderthals were roughly 40 percent less fit than modern humans, meaning they were less likely to produce offspring. More. Okay, so it turns out we didn’t murder them, like everyone said we had. That’s the trouble when you’re supposed to be extinct. People can insist that Neanderthals are the Bad Seed and they can’t launch a grievance. Fortunately, even if it’s nonsense, no one gets hurt. Far cry from eugenics. See also: There’s a gene for that… or is there? and Neanderthal Man: The long-lost relative turns up Read More ›

Some of us hacks did not know this: There is a second layer of information above DNA sequences, partly mechanical and partly tied to nucleosome positions. Currently fronted at Phys.org with the usual accompanying nonsense File with: Darwinism is nuts. See also: Promoting purpose in nature without design? Follow UD News at Twitter!