tagged w/ Genetics
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Starting with results of the Nazi elimination of diagnosed schizophrenics, Levine re-examines the evidence for the heritability of mental illness and offers some suggestions about Western civilization and our shared humanity.Starting with results of the Nazi elimination of diagnosed schizophrenics, Levine... more
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The world's first geneticallymodified humans have been created, it was revealed last night. The disclosure that 30 healthy babies were born after a series of experiments in the United States provoked another furious debate about ethics. So far, two of the babies have been tested and have been found to contain genes from three 'parents'.
Fifteen of the children were born in the past three years as a result of one experimental programme at the Institute for Reproductive Medicine and Science of St Barnabas in New Jersey.
The babies were born to women who had problems conceiving. Extra genes from a female donor were inserted into their eggs before they were fertilised in an attempt to enable them to conceive. Genetic fingerprint tests on two one-year- old children confirm that they have inherited DNA from three adults --two women and one man.
The fact that the children have inherited the extra genes and incorporated them into their 'germline' means that they will, in turn, be able to pass them on to their own offspring. Altering the human germline - in effect tinkering with the very make-up of our species - is a technique shunned by the vast majority of the world's scientists.
Geneticists fear that one day this method could be used to create new races of humans with extra, desired characteristics such as strength or high intelligence.
Writing in the journal Human Reproduction, the researchers, led by fertility pioneer Professor Jacques Cohen, say that this 'is the first case of human germline genetic modification resulting in normal healthy children'. Some experts severely criticised the experiments. Lord Winston, of the Hammersmith Hospital in West London, told the BBC yesterday: 'Regarding the treat-ment of the infertile, there is no evidence that this technique is worth doing . . . I am very surprised that it was even carried out at this stage. It would certainly not be allowed in Britain.'
John Smeaton, national director of the Society for the Protection of Unborn Children, said: 'One has tremendous sympathy for couples who suffer infertility problems. But this seems to be a further illustration of the fact that the whole process of in vitro fertilisation as a means of conceiving babies leads to babies being regarded as objects on a production line.
'It is a further and very worrying step down the wrong road for humanity.' Professor Cohen and his colleagues diagnosed that the women were infertile because they had defects in tiny structures in their egg cells, called mitochondria.
They took eggs from donors and, using a fine needle, sucked some of the internal material - containing 'healthy' mitochondria - and injected it into eggs from the women wanting to conceive. Because mitochondria contain genes, the babies resulting from the treatment have inherited DNA from both women. These genes can now be passed down the germline along the maternal line.
A spokesman for the Human Fertilisation and Embryology Authority (HFEA), which regulates 'assisted reproduction' technology in Britain, said that it would not license the technique here because it involved altering the germline.
Jacques Cohen is regarded as a brilliant but controversial scientist who has pushed the boundaries of assisted reproduction technologies.
He developed a technique which allows infertile men to have their own children, by injecting sperm DNA straight into the egg in the lab. Prior to this, only infertile women were able to conceive using IVF. Last year, Professor Cohen said that his expertise would allow him to clone children --a prospect treated with horror by the mainstream scientific community.
'It would be an afternoon's work for one of my students,' he said, adding that he had been approached by 'at least three' individuals wishing to create a cloned child, but had turned down their requests.
http://abcnews.go.com/Health/story?id=117472
http://www.dailymail.co.uk/news/article-43767/Worlds-GM-babies-born.html
http://5magazine.files.wordpress.com/2011/01/designer-baby.jpgThe world's first geneticallymodified humans have been created, it was revealed... more
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This is a TED talk and not an actual article. I decided to submit it because it's freaking cool and happens to touch on a lot of hot button issues in scifi. Evolution, digitizing memories / minds, cloning, biological / cybernetic enhancements and biological immortality are all there so enjoy.
I'm hoping this is not going to be one of those early 20th century pipedreams because I really want some robot arms before I kick the bucket.
http://www.ted.com/talks/juan_enriquez_will_our_kids_be_a_different_species.htmlThis is a TED talk and not an actual article. I decided to submit it because it's... more
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Technological advances have benefitted humanity; we can all see how fitting prosthetic limbs to amputees can raise no moral objections. But how might we respond if designers invite us to upgrade to Arm 2.0 or Brain 4.0? Is there a point where technology transforms what it means to be human and should we be wary or embrace it? Speakers include Daisy Ginsberg, design fellow, Synthetic Aesthetics, Stanford University/University of Edinburgh; Professor Andy Miah, director, Creative Futures Research Centre, University of West Scotland; Marilyn Mond, emeritus professor of molecular embryology, University College London; Susana Soares, designer; senior lecturer, London Southbank University.Technological advances have benefitted humanity; we can all see how fitting prosthetic... more
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Some have thought flowers' look was due to painter's alleged mental illness
The whimsical appearance of some of the sunflowers in Vincent van Gogh's paintings isn't the result of the painter's alleged mental illness. Researchers have found that overly-bushy sunflowers are actually the result of a genetic mutation in some strains of the flowers.
The typical sunflower has a brown, seed-filled middle and a ring of yellow petals, but some seem overgrown with petals in "double rows" — like one variety called the "Teddy Bear" — and others have scrawny petals and seeds extending nearly to the edge of the flower. The researchers discovered that a genetic mutation is to blame for these differences.
"In addition to being of interest from a historical perspective, this finding gives us insight into the molecular basis of an economically important trait," study researcher John Burke, at the University of Georgia, said in a statement. "You often see ornamental varieties similar to the ones Van Gogh painted growing in people's gardens or used for cut flowers, and there is a major market for them."
Sunflower heads — actually multiple small flowers called florets — have a very specific symmetry. The "seeds" are laid out in a special geometric pattern. In a normal sunflower, the outer florets sprout into petals and the inner ones mature into seeds.
To understand the genetic basis of this difference, Burke and his colleagues began by making sunflower babies that were a blend of the regular breed and a variety of bushy sunflower. The pattern they saw indicated that a single, dominant gene was responsible for the bushy flowers seen in Van Gogh's paintings.
To double-check their results, they sequenced this gene and looked for it in several commercially available types of sunflowers. They never saw the mutation in flowers that had the traditional sunflower appearance, but always saw it in the fluffy varieties.
The newly discovered mutation changes how the plant regulates where the line between "petals" and "seeds" is drawn. When mutated, the gene can move this boundary either closer to the center of the flower head or farther away from it and closer to the outer layers of florets.
If the boundary line moves toward the center, the flower loses the traditional "sunflower" appearance and looks more like the "Teddy Bear" sunflower. If it moves outward, the flower has more seeds and a dinky layer of petals.
"All of this evidence tells us that the mutation we've identified is the same one that Van Gogh captured in the 1800s," Burke said.
The study was published Thursday in the journal PLoS Genetics.Some have thought flowers' look was due to painter's alleged mental illness... more
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CNN...
First gorilla genome map offers clues to human evolution
By Matthew Knight, CNN
updated 12:17 PM EST, Thu March 8, 2012 | Filed under: Innovations
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STORY HIGHLIGHTS
Scientists have completed the DNA map of an African western lowland gorilla
Research hopes to shed light on human evolution and biology
Western lowland gorilla population estimated to be 100-200,000 individuals in the wild
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(CNN) -- The first complete gorilla genome has been mapped by scientists giving fresh insights into our own origins.
Gorilla are the last of the genus of living great apes (humans, chimpanzees, gorillas and orang-utans) to have their DNA decoded, offering new perspectives on their evolution and biology.
"The gorilla genome is important because it sheds light on the time when our ancestors diverged from our closest evolutionary cousins around six to 10 million years ago," says Aylwyn Scally, postdoctoral fellow at the Wellcome Trust Sanger Institute, Cambridge and lead author of the report.
"It also lets us explore the similarities and differences between our genes and those of gorilla, the largest living primate," he added.
A team of researchers examined more than 11,000 genes in humans, chimpanzees and gorillas, looking for evolutionary clues.
Initial findings have revealed that 15% of the gorilla genome is closer to human DNA than to our nearest evolutionary relative, the chimpanzee.
Researchers found that genes relating to sensory perception, hearing and brain development showed "accelerated evolution" in all three, but particularly in humans and gorillas.
Having the entire length of the gorilla genome now means scientists can start to compare all the four great apes at every position on the genome, Scally says.
It forms the baseline, he says, from which to move forwards and really explore why and when our genes and those of the great apes diverged.
"Did it happen quite quickly or was it something that gradually happened? At the moment we don't know," he said.
"It could have been some climatic change that separated humans in the east of Africa from chimpanzees in the forest -- that's an idea some have floated. If we can see some imprint of it in the genome that would very, very useful information."
Scientists used the DNA of a female western lowland gorilla (called Kamilah) who resides at San Diego Zoo.
In the wild, it is the most widespread species of gorilla, according to the World Wildlife Fund (WWF), with a estimated population of 100-200,000 individuals.
The majority are found in Cameroon, Central African Republic, west Congo, Equatorial Guinea, Gabon and Angola.
It's cousin, the eastern lowland gorilla is less prevalent (fewer than 20,000 individuals) and can only be found in the rainforests of the eastern Democratic Republic of Congo, says WWF.
The research is published in the science journal Nature.
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PHOTO (ABOVE):
The complete DNA of a female western lowland gorilla called Kamilah (left) has been mapped by scientists, completing the set of genomes for all great apes (humans, chimpanzees, gorillas and orang-utans).
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.CNN...
First gorilla genome map offers clues to human evolution
By Matthew... more
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NOTE: A highly informative appeal for support from the STOP GE Trees Campaign - a great organisation. For more on their work and how to get involved: http://globaljusticeecology.org/stopgetrees.php?tabs=0
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Our plans for the STOP GE Trees Campaign in 2012 and our accomplishments from 2011
The years 2012 and 2013 could be the most important yet for our campaign to ban the release of genetically engineered trees (GE trees) into the environment.
* Countering Phony Sustainability Criteria: The timber industry is moving forward with plans to develop phony so-called "sustainability criteria" for GE trees. This is crucial if they want to get GE trees certified by bodies like the Forest Stewardship Council (FSC), which would make it easier to get investors. Right now the FSC will not certify GE trees.
GE trees are not now and never will be "sustainable." They deplete soils and water, require huge inputs of toxic chemicals, replace native forests, displace biodiversity and forest dependent communities, kill beneficial insects, and worsen climate change. So in order to combat the sustainability lie, we are increasing our work to expose the social and ecological dangers of GE trees.
* GE Eucalyptus Trees in the US South: In January 2011, GE tree company ArborGen applied for permission from the US Department of Agriculture (USDA) to sell billions of their GE eucalyptus trees for commercial plantations across seven states in the US South--from Texas to South Carolina.
We are mobilizing to ensure this never happens.
* GE Poplars in the Pacific Northwest: GE poplar trees are emerging as a major threat in California and the Pacific Northwest. Scientists at the University of Oregon and the University of Washington have received large federal grants to develop genetically engineered poplar trees for bioenergy plantations.
GE poplar trees are extremely dangerous because native wild poplars grow in forests in California and the Pacific Northwest. These native poplars could easily be contaminated with pollen from the GE poplars. This irreversible contamination would be disastrous for forests, wildlife, soils, insects and songbirds. And once GE tree contamination begins, there is no way to stop it from continuing to spread.
We will be escalating our work in the Pacific Northwest in 2012 to stop GE poplars. Let us know if you can help!
The good news--we can still stop the disaster of GE trees before it is too late. Since 1999 we havesuccessfully prevented commercialization of GE trees because of the support of people like you. You enable us to stand up against the largest timber corporations on the planet. Thank you.
Because of our success, the promoters of GE trees name GJEP as the main obstacle to their forward progress.
After we filed a lawsuit against the USDA in July 2010 over their approval of a large field trial of GE eucalyptus trees, Biomass Magazine stated that our lawsuit was scaring away investors from supporting GE tree research because no one wants to invest in a technology that is going to be tied up for years in legal battles. As a result, GE tree company ArborGen decided not to go public with their stock only days before they were scheduled to do so.
The victories of the STOP GE Trees Campaign over the years show the power of grassroots organizing, alliance building, non-violent action and our refusal to compromise.
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This is the documentary, A Silent Forest, narrated by Dr. David Suzuki that lays out the threat of genetically engineered trees which are still a threat to the U.S.NOTE: A highly informative appeal for support from the STOP GE Trees Campaign - a... more
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Co-authored by U.S. Rep. Pete Stark (D-CA) and American Humanist Association Executive Director Roy Speckhardt.
On Feb. 12 we'll commemorate the anniversary of Charles Darwin's birth, a celebration around the world known as Darwin Day, to appreciate the advancement of human knowledge and the achievements of science and reason. It must also be a day when we push back against the politicization and undermining of science by ideologues and zealots.
We owe a debt of gratitude to Charles Darwin, who changed the course of human history by bringing science and reason to the fore. His theory of evolution by natural selection not only provided a compelling explanation for the diversity of life on earth, it became the foundation of modern biology, genetics, and medicine. His scientific curiosity and discovery led to breakthroughs that have helped humanity solve innumerable problems and improve our quality of life.
To read the rest of this Huffington Post article, click here: http://hmn.st/yxU8iLCo-authored by U.S. Rep. Pete Stark (D-CA) and American Humanist Association Executive... more
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Frank will talk about, the Roman cult, law, sovereignty, history of the Venetians, the Khazarians and other related global issues. Topics Discussed: the Roman law system, Egypt, naming, power, Ebla, Yahudi, Menashe, Etruscans, occupation, Latin, cursive, land, registers, Khazaria, King Tut, Justinian, Belarus, genetic anomaly, black plague.
Frank'O Collins is an author and futurist having developed over 60 web sites on global issues and solutions. 25 years ago.Frank's current focus is finishing the 22 books of Canon law, based on the "Restore the Law Project," aimed at challenging the root of Roman Vatican law, 500 years since Martin Luther first challenged the authority of the Vatican and its commercial allies.
http://www.redicecreations.com/radio/2011/11/RIR-111124.phpFrank will talk about, the Roman cult, law, sovereignty, history of the Venetians, the... more
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Dagum
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1 year ago
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White Tigers do not exist in the wild, they are purposefully inbred in captivity to meet the demand of the paying public. The kind of severe inbreeding that is required to produce the mutation of a white coat also causes a number of other defects in these big cats.
The same gene that causes the white coat causes the optic nerve to be wired to the wrong side of the brain, thus all white tigers are cross eyed, even if their eyes look normal. They also often suffer from club feet, cleft palates, spinal deformities and defective organs.White Tigers do not exist in the wild, they are purposefully inbred in captivity to... more
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BigCat
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Admitted government projects relating to genetically engineered weapons that could be used to eliminate entire ethnic groups.
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There's no coincidence that the most famous people in politics, royalty, banking, news and entertainment are all related. Enjoy your vaccine.Admitted government projects relating to genetically engineered weapons that could be... more
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Two brothers, both alike in heritage, but as different as black and white. Ebony and ivory. Night and day. You get it. If one thing's clear about 18-year-old British twins James and Daniel Kelly, it's that they never get confused for one another.
James and Daniel are the human version of a black and white cookie. Born to Alyson and Errol Kelly, an interracial couple, they display the unusual characteristic of being a pair of one dark-skinned and one-light skinned twins, reports the Guardian.
(MORE: Why DNA Isn't Your Destiny)
So how did this genetic anomaly occur?
Dr. Jim Wilson, a population geneticist at Edinburgh University, tells the Guardian that the cause is the father's heritage. Errol, Jamaican by background, holds the genetic key to skin color variations among offspring.
"It wouldn't really be possible for a black African father and a white mother to have a white child, because the African would carry only black skin gene variants in his DNA, so wouldn't have any European DNA, with white skin variants, to pass on," he explains.
However, Wilson also tells the Guardian that people of Caribbean descent are often likely to carry European DNA. Which, if you can remember back to your high school biology unit on genetics, is enough to create a striking difference.
"The Caribbean father will have less European DNA than African DNA, so it's more likely he'll pass on African DNA – but rarely, and I've worked it out to be around one in 500 sets of twins where there's a couple of this genetic mix, the father will pass on a lot of European DNA to one child and mostly African DNA to the other. The result will be one white child and one black."
Read more: http://newsfeed.time.com/2011/09/27/surprising-siblings-black-and-white-brothers-are-actually-twins/#ixzz1ZACxvWLO
http://newsfeed.time.com/2011/09/27/surprising-siblings-black-and-white-brothers-are-actually-twins/?xid=rss-politics-huffpoTwo brothers, both alike in heritage, but as different as black and white. Ebony and... more
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mab001
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1 year ago
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We have come a long way from the days of Dicken’s Oliver Twist singing “Food Glorious Food” while eating gruel. One would thing that our food chain has improved greatly since those days of workhouses and debtor prisons. For a while I think we did.We have come a long way from the days of Dicken’s Oliver Twist singing... more
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The story of Dr. David Suzuki, the environmental conscience of Canada who has strived all of these years to bring us truth. As he stated, we are now a force of nature.
This movie is now on DVD for anyone interested.The story of Dr. David Suzuki, the environmental conscience of Canada who has strived... more
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“Chemists have created an artificial genetic code capable of evolving to produce new genes. The code consists of six bases, rather than the standard four, and could form the basis of randomly mutating synthetic life. Steven Benner, at the Foundation for Applied Molecular Evolution, US, credited as the man who kick-started the field of 'synthetic biology', is behind the work. Benner created two new molecules which can be slotted into DNA alongside regular adenine (A), thymine (T), cytosine (C) and guanine (G) bases. The new bases, dubbed 'P' and 'Z,' look similar to natural ones but have orthogonal hydrogen bonding patterns”
http://www.rsc.org/chemistryworld/News/2011/August/23081104.asp“Chemists have created an artificial genetic code capable of evolving to produce... more
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"With the novel use of a technique that uses light to control brain cells, Stanford University researchers have shown that fragmented sleep causes memory impairment in mice.""With the novel use of a technique that uses light to control brain cells,... more
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Leading research organisations and patient groups are asking the government to change the law to allow scientists to implant embryos into women that have genetic material from three different parents.This "tiny" bit of third person's DNA can prevent inherited disorders being passed on researchers claim. The groundbreaking procedure has so far only been tried in a lab and mostly using animal embryos. But if it proves safe and successful it could prevent several hundred babies every year being born with genetic defects.The afflictions can include blindness, organ failure, muscular disorders, learning disabilities and diabetes. Many babies die as a result of the genetic defects.The diseases are caused by mutations in the mitochondrial DNA, which is found only in the egg of the mother.British scientists have led efforts to find ways to prevent inherited disorders being passed on and causing babies to die or be disabled.The call for a law change comes in a letter sent to Andrew Lansley, the health secretary. The letter, from the Wellcome Trust, Academy of Medical Sciences, Medical Research Council and Muscular Dystrophy Campaign, among others, was dispatched as a group of experts published a review commissioned by Lansley into the safety and effectiveness of scientific procedures attempted so far.How do they do it?There are two separate techniques - both of which involve mixing the DNA of the parents with a small amount of mitochondrial DNA from a donor egg.This is not, however, "three-parent IVF", said Professor Robin Lovell-Badge, one of the authors of the review which has now gone to the government. "It is not a term we have used once in this report and it is not a term that should be used," he told the Guardian."This is a tiny, tiny bit of DNA. It is not carrying any characteristics except that you have normally functioning mitochondria."The DNA contribution from the egg with normal mitochondria is tiny compared to the DNA from the two main parents.Dr Evan Harris, the former Lib Dem MP who has taken a close interest in embryo research, likened it to "changing the battery on the laptop, but not affecting the information on the hard disk".One of the two experimental techniques is called maternal spindle transfer and involves removing the genetic material from the would-be mother's unfertilised egg and fusing it into a donor egg from which the nucleus has been removed. Fertilisation with the partner's sperm takes place afterwards."It's been done in various animals and seems to be both efficient and safe," said Lovell-Badge. But it has not been tried using human eggs, which the scientists would like to see happen.The other method is proncuclear transfer, which has been researched by the Institute of Genetic Medicine at Newcastle University. This involves the transfer of both parents' DNA from a fertilised egg into a fertilised donor egg which has had its nucleus removed. This was successfully carried out in mice as early as the 1980s, and in Newcastle has also been done with abnormal human eggs.Lovell-Badge and his team would like to see this attempted in normal fertilised human eggs and also in monkeys, to be sure of the safe outcome.The further experiments should not take much more than a year. Scientists and patient groups are now pressing the government to consider the legal and ethical issues involved, so that the necessary regulatory changes can be made to move the experimental work into the clinic as soon as possible.
Source: http://www.guardian.co.uk/science/2011/apr/19/scientists-embryos-three-parents Leading research organisations and patient groups are asking the government to change... more
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'Naked' penguins have scientists perplexed
Photo: A worker puts a wetsuit on a featherless penguin to keep her warm, earlier this week, at the Jurong Bird Park in Singapore.
April 8th, 2011
03:40 PM ET
A mysterious ailment is causing penguins to lose their feathers, according to researchers at the Wildlife Conservation Society.
The condition, called feather-loss disorder, has been seen in penguin chicks in both sides of the Atlantic Ocean the past few years and is featured in a recent edition of the journal "Waterbirds," the release said.
While scientists don't know what could cause a penguin to go "naked," possible culprits include genetics, nutrient imbalances, thyroid disorders or germs.
“We need to conduct further study to determine the cause of the disorder and if this is in fact spreading to other penguin species,” Dee Boersma, who has studied Magellanic penguins, said in the release.
Feather loss in pet birds has long been a common ailment seen by pet stores and private owners, but researchers studying the penguins in the Atlantic said this is something different.
“The recent emergence of feather-loss disorder in wild bird populations suggests that the disorder is something new,” Mariana Varese, acting director of the society’s Latin America and Caribbean program, is quoted as saying in the release. “More study of this malady can help identify the root cause, which in turn will help illuminate possible solutions,” she said.
While the illness does not appear to be fatal, the sick birds, unlike their feathered counterparts, linger in the sun instead of seeking refuge from the midday heat. That behavior has led to several deaths, according to the release.
Disease is not the only recent peril that Atlantic penguins have faced.
A few weeks ago, volunteers from Nightingale Island, a British territory that is part of the Tristan da Cunha archipelago, mobilized to save tens of thousands of Northern Rockhopper penguins threatened by an oil spill.
It has been a surreal year in animal deaths. In January, tens of thousands of birds and fish were found dead in countries around the world.
Recently dolphins, some with oil inside them, have turned up dead in the Gulf of Mexico. Scientists don’t know why.
"Even though they have oil on them, it may not be the cause of death," Blair Mase, the National Oceanic and Atmospheric Administration's marine mammal investigations coordinator, told CNN. "We want to look at the gamut of all the possibilities."'Naked' penguins have scientists perplexed
Photo: A worker puts a... more
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The alarming condition of sea life and the seafood supply present even before the 2010 oil spill in Louisiana; also what's in your new car smell can hurt you. Nancy Mroczek PhD - www.nancymroczek.comThe alarming condition of sea life and the seafood supply present even before the 2010... more
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thttp://www.wired.com/wiredscience/2011/02/fish-toxins-environment/
Some fish in New York’s Hudson River have become resistant to several of the waterway’s more toxic pollutants. Instead of getting sick from dioxins and related compounds including some polychlorinated biphenyls, Atlantic tomcod harmlessly store these poisons in fat, a new study finds.
But what’s good for this bottom-dwelling species could be bad for those feeding on it, says Isaac Wirgin of the New York University School of Medicine’s Institute of Environmental Medicine in Tuxedo. Each bite of tomcod that a predator takes, he explains, will move a potent dose of toxic chemicals up the food chain — eventually into species that could end up on home dinner tables.
From 1947 to 1976, two General Electric manufacturing plants along the Hudson River produced PCBs for a range of uses, including as insulating fluids in electrical transformers. Over the years, PCB and dioxin levels in the livers of the Hudson’s tomcod rose to become “among the highest known in nature,” Wirgin and his colleagues note online Feb. 17 in Science. Because these fish don’t detoxify PCBs, Wirgin explains, it was a surprise that they could accumulate such hefty contamination without becoming poisoned. His team now reports that the tomcod’s protection traces to a single mutation in one gene. The gene is responsible for producing a protein needed to unleash the pollutants’ toxicity.
All vertebrates contain molecules in their cells that will bind to dioxins and related compounds. Indeed, these proteins — aryl hydrocarbon receptors, or AHRs — are often referred to as dioxin receptors. Once these poisons diffuse into an exposed cell, each molecule can mate with a receptor and together they eventually pick up a third molecule. This trio can then dock with select segments of DNA in the cell’s nucleus to inappropriately turn on genes that can poison the host animal.
The tomcod actually has two types of AHRs, with AHR-2 offering the most effective binding to dioxin-like pollutants. But one naturally occurring AHR-2 variant, the result of a gene mutation, proves a very poor mate, Wirgin’s team has found. It takes five times more of the pollutants to get substantial binding than is needed with the conventional AHR-2.
In local rivers relatively free of dioxins and PCBs, 95 percent of tomcod possess AHR-2 only in the conventional form. But in the PCB-rich Hudson, Wirgin’s group finds, the only kind of AHR-2 protein in 99 percent of tomcod is the poorly binding variant.
The mutant receptor appears to have evolved long ago and to be widely dispersed. But in the Hudson, fish with the gene to make the mutant receptor have thrived, while those without it have died out, Wirgin notes.
Adaptation to resist poisons occurs throughout biology, observes molecular toxicologist John Stegeman of the Woods Hole Oceanographic Institution in Massachusetts. This process explains why some pesticides no longer kill their targets and why some microbes become immune to antibiotics.
Stegeman has been chronicling resistance to toxic PCBs and polycyclic aromatic hydrocarbons in another coastal species, a killifish. “But the mechanism in the killifish has not been uncovered, despite a long effort to determine it,” he says.
Knowing the genetic underpinnings for chemical resistance can help predict the likelihood of that resistance developing, he explains, and can point to “how one might exploit resistance — even understand why chemicals are toxic.” Genetic mechanisms for chemical resistance in wild species are known for some invertebrates, such as bugs. Stegeman says, to his knowledge, this tomcod finding is the first in a vertebrate.thttp://www.wired.com/wiredscience/2011/02/fish-toxins-environment/
Some fish in... more
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