79 posts tagged genetics
Phobias may be memories passed down in genes from ancestors
Memories may be passed down through generations in DNA in a process that may be the underlying cause of phobias
Memories can be passed down to later generations through genetic switches that allow offspring to inherit the experience of their ancestors, according to new research that may explain how phobias can develop. Scientists have long assumed that memories and learned experiences built up during a lifetime must be passed on by teaching later generations or through personal experience. However, new research has shown that it is possible for some information to be inherited biologically through chemical changes that occur in DNA. Researchers at the Emory University School of Medicine, in Atlanta, found that mice can pass on learned information about traumatic or stressful experiences – in this case a fear of the smell of cherry blossom – to subsequent generations. The results may help to explain why people suffer from seemingly irrational phobias – it may be based on the inherited experiences of their ancestors. (via Phobias may be memories passed down in genes from ancestors - Telegraph)
Harvey Fineberg: Are we ready for neo-evolution?
Medical ethicist Harvey Fineberg shows us three paths forward for the ever-evolving human species: to stop evolving completely, to evolve naturally — or to control the next steps of human evolution, using genetic modification, to make ourselves smarter, faster, better. Neo-evolution is within our grasp. What will we do with it?
Jealousy: it’s in your genes
The green-eyed monster of jealousy may be hardwired into our DNA, but there is a lot we can do to keep it under control
How would you feel if you suspected your partner had enjoyed a one-night stand while away on holiday without you? What if, instead of having sex on the trip, you believed she or he had fallen in love with someone? In either case, if your partner will probably never see the other person again, would that make the situation any easier to cope with? Faced with either scenario, most of us would feel intensely jealous: it’s a very basic, normal reaction. But does the universality of jealousy indicate that it might be genetically programmed? The first study to investigate the genetic influence on jealousy was recently published. Researchers put the questions at the top of this article to more than 3,000 pairs of Swedish twins. Fraternal twins share about 50% of their genes; identical twins share exactly the same genetic make-up. By comparing the answers given by each group of twins, the researchers were able to show that around one third of the differences in levels of jealousy across the population are likely to be genetic in origin. In both scenarios – fears about a partner sleeping with or falling in love with a stranger – women reported more jealousy than men. But the researchers also found a gender difference between relative reactions to the idea of sexual or emotional betrayal. Men were far more troubled by the thought that a partner had been sexually unfaithful than by potential emotional infidelity. Women tended to respond to each scenario with equal levels of jealousy. Why is this? The answer, according to some scientists, may lie in evolutionary pressures. For both men and women, reproduction is key. But men, unlike women, cannot be certain that they are the biological parent of their child, and so they are naturally more perturbed at the thought of sexual infidelity than they are about emotional infidelity – because it jeopardises the successful transmission of their genes. Women, though relatively less perturbed by the idea that their partner may have been sleeping around, are nevertheless dependent on their mate for their survival and that of their offspring.
Sometime in the not-too-distant future, Marie and Antonio Freeman step into a doctor’s office to design their next child. “Your extracted eggs, Marie, have been fertilized with Antonio’s sperm,” the doctor says. “After screening we’re left with, as you see, two healthy boys and two very healthy girls.” A monitor displays what looks like soap bubbles that bumped into each other on a green background. “Naturally, no critical predispositions to any of the major heritable diseases,” the doctor says. “All that remains is to select the most compatible candidate. We might as well start with gender—have you given it any thought?” “We would want Vincent to have a brother, you know, to play with,” Marie says, referring to her first child. Acknowledging this, the doctor continues: “You have specified hazel eyes, dark hair and fair skin. I have taken the liberty of eradicating any potentially prejudicial conditions: premature baldness, myopia, alcoholism and addictive susceptibility, propensity for violence and obesity—” “We didn’t want—I mean, diseases, yes,” Marie interrupts. “Right, we were wondering if it’s good to leave a few things to chance,” Antonio says. “You want to give your child the best possible start,” the doctor replies. “Believe me, we have enough imperfection built-in already. Your child doesn’t need any additional burdens. And keep in mind, this child is still you, simply the best of you. You could conceive naturally a thousand times and never get such a result.” The Freemans are characters in the science fiction film Gattaca, which explores liberal eugenics as an unintended consequence of certain technologies meant to assist human reproduction. Although Antonio and Marie do not exist outside the movie’s imaginary universe, their real-life counterparts could be walking among us sooner than we think—and, in a sense, they already are.
Scientists are starting to understand why one person’s face can look so different from another’s.
Working on mice, researchers have identified thousands of small regions of DNA that influence the way facial features develop. The study also shows that tweaks to genetic material can subtly alter face shape. The findings, published in Science, could also help researchers to learn how facial birth defects arise. The researchers said that although the work was carried out on animals, the human face was likely to develop in the same way. Professor Axel Visel, from the Joint Genome Institute at the Lawrence Berkeley National Laboratory in California, told BBC News: “We’re trying to find out how these instructions for building the human face are embedded in human DNA. “Somewhere in there there must be that blueprint that defines what our face looks like.” (via BBC News - Light shed on how genes shape face)
The Biblical parable of the Good Samaritan, a traveler who stops on the road to help a badly wounded robbery victim that others had passed by, is a story that we see repeated again and again in the news. In Fort Lauderdale, Fla., after a woman lost control of her car on an Interstate freeway and flipped into a water-filled ditch, a man jumped in to rescue her from drowning. In Arizona, after a community college student lost a wallet containing her cash, credit cards, student ID and immigrant work permit, an unidentified person found it and dropped it off at her school’s office. In Oklahoma, after a teenage skateboarder tumbled from his board and suffered a concussion, a man he didn’t know found him by the side of the road and took him to get help. What motivates people to stop and help others that they didn’t previously know, with no apparent benefit to themselves? Traditionally, we’ve viewed people who engage in prosocial behavior — that is, voluntary acts performed to benefit others or society as a whole — as being motivated by moral character or spiritual beliefs. But in recent years, increasing evidence has emerged to suggest that the tendency to be a do-gooder may be influenced by genes. In a newly-published study in the journal Social Neuroscience, for example, researchers found that a single variation in a genotype seems to affect whether or not a person engages in prosocial acts. Individuals who have one variation of the genotype have a tendency toward social anxiety — that is, unease around other people, and are less inclined to help others in ways that involve personal interaction.
Researchers rewrite an entire genome — and add a healthy twist
Scientists from Yale and Harvard have recoded the entire genome of an organism and improved a bacterium’s ability to resist viruses, a dramatic demonstration of the potential of rewriting an organism’s genetic code. “This is the first time the genetic code has been fundamentally changed,” said Farren Isaacs, assistant professor of molecular, cellular, and developmental biology at Yale and co-senior author of the research published Oct. 18 in the journal Science. “Creating an organism with a new genetic code has allowed us to expand the scope of biological function in a number of powerful ways.” The creation of a genomically recoded organism raises the possibility that researchers might be able to retool nature and create potent new forms of proteins to accomplish a myriad purposes — from combating disease to generating new classes of materials. The research — headed by Isaacs and co-author George Church of Harvard Medical School — is a product of years of studies in the emerging field of synthetic biology, which seeks to re-design natural biological systems for useful purposes. In this case, the researchers changed fundamental rules of biology. (via YaleNews | Researchers rewrite an entire genome — and add a healthy twist)
Researchers at IGS, the genomic and structural information laboratory (CNRS/Aix-Marseille University), working in association with the large-scale biology laboratory (CEA/Inserm/Grenoble Alpes University) have just discovered two giant viruses which, in terms of number of genes, are comparable to certain eukaryotes, microorganisms with nucleated cells. The two viruses – called “Pandoravirus” to reflect their amphora shape and mysterious genetic content – are unlike any virus discovered before. This research appeared on the front page of Science on July 19, 2013. (via Pandoravirus: missing link discovered between viruses and cells)
Genepeeks firm to offer ‘digital baby’ screen for sperm donors
A service that digitally weaves together the DNA of prospective parents to check for potential disease in thousands of “virtual babies” is set to launch in the US by December. New York start-up Genepeeks will initially focus on donor sperm, simulating before pregnancy how the genetic sequence of a female client might combine with those of different males. Donors that more often produce “digital children” with a higher risk of inherited disorders will be filtered out, leaving those who are better genetic matches. Everything happens in a computer, but experts have raised ethical questions. “We are just in the business right now of giving prospective mothers, who are using donor sperm to conceive, a filtered catalogue of donors based on their own underlying genetic profile,” Genepeeks co-founder Anne Morriss told BBC News. “We are filtering out the donor matches with an elevated risk of rare recessive paediatric conditions.” Ms Morriss, an entrepreneur, gave a presentation on the company at the Consumer Genetics Conference in Boston last week. (via BBC News - Genepeeks firm to offer ‘digital baby’ screen for sperm donors)
Genome search still can’t explain lefties
New research rules out a “strong genetic determinant” in influencing left- or right-handedness. The researchers conducted a twin study examining the whole genome—which contains hereditary information—of nearly 4,000 subjects from the London Twin Research Unit to compare left- and right-handed participants. Their findings are published in the journal Heredity. The study was unable to find a strong genetic factor in determining handedness. If there was a single major genetic determination of handedness, there should be a detectable shift between left- and right-handed people in the frequency of variants in that part of the genome—and this isn’t the caseStudy author John Armour, professor of human genetics at the University of Nottingham, says: “There should be a detectable shift between right- and left-handed people because modern methods for typing genetic variation cover nearly all of the genome. A survey that compared the whole-genome genotypes for right- and left-handed people should leave such a gene nowhere to hide.” (via Genome search still can’t explain lefties | Futurity)