People with milk allergies often turn to products like rice and soy milks. But now, in a twist, there is a new source of hypoallergenic milk in the offing: genetically-modified cows.
It has been a summer of withered crops and wildfires, the U.S.’s driest in the last fifty years, during which 55 percent of the U.S. has experienced a drought. And of the land dedicated to corn production, 87 percent has been dry.
Over at Technology Review, Jessica Leber wrote about an engineering solution to the problem of parched corn: seeds bred or genetically enhanced to resist drought, some of which have been tested this summer and will be sold by three big seed companies next year.
A pest-eating ladybug attacks an aphid.
As angry debates about genetic modification continue, GM crops are quietly going about their business—and producing some positive side effects. In China, with Bt cotton reducing the need for insecticides, pest-eating bugs have rebounded and brought natural pest control with them.
China’s genetically modified cotton is not new. Farmers used to spray their cotton with a protein, naturally produced by the Bacillus thuringiensis (Bt) bacteria, which is toxic to certain insects. As research into genetically modified crops advanced, scientists implanted the cotton itself with the Bt genes that code for production of the insect toxin, creating so-called “Bt cotton” and alleviating the need for the sprayed insecticide. Since China approved its use in 1997, Bt cotton has proved itself particularly effective against the cotton bollworm moth, reducing the costs and side effects of spraying pesticides, but it has had may also decrease the number of non-pest insects compared with organic fields.
With the advent of Bt cotton, pesticide use became specialized, only affecting insects that both were vulnerable to Bt’s toxin and that fed on cotton, which allowed the populations of other insect species to rebound. Some of the now-thriving species, like mirids, are pests, but others eat pests, and their recovery is making natural bug control possible.
DNA is a great way to store information—just ask your cells. Its molecules are stable, and billions of base pairs coil neatly into a few microns in a cell nucleus. While it’s easy for a cell to read information from DNA, a cell can’t rewrite new data into its DNA sequence.
But now synthetic biologists at Stanford have managed to pull off that very trick. To do so, they had to abandon the genetic code of ATCG and get a DNA sequence to act like bits—pieces of binary information—in a computer. The memory system uses two enzymes that can cut out and reintegrate a sequence of DNA in a live cell. Crucially, the attachment sites are designed so that the DNA sequence can be flipped every time it is put back in. The sequence oriented one way would represent 1, and its inversion is 0.
With some clever genetic engineering but without ever touching a cell or an animal, scientist can remotely control cells using ultrasound, light, and, now, also radio waves. The electromagnetic waves can be used to selectively heat up parts of cells and activate a gene to make insulin in mice, according to a recent study published in Science.
But why care about radio waves if we have light and ultrasound? Radio waves have a couple distinct advantages over existing techniques.
In the current study, the radio waves didn’t heat up a whole patch of tissue or even a whole cell—it only affected specific pores in the cell, called TRPV1, that open in response to heat. To get this specificity, the scientists made special iron oxide nanoparticles attached to an antibody that only sticks to TRPV1. When they turned on the radio waves, the iron oxide particles warmed up and opened the TRPV1 channel, minimally affecting the rest of the cell or surrounding cells. Ultrasound, on the other hand, heats up a whole patch of tissue to 42° Celsius, which could have damaging or confounding effects on the cells.
The AquAdvantage salmon.
When most people say “genetically modified organism,” they usually mean a plant—corn, perhaps, or an eggplant. But that may soon change. The FDA has completed its analysis of the first genetically modified animal likely to hit supermarket shelves: the AquAdvantage salmon, made by Massachusetts-based AquaBounty Technologies, Inc. Thanks to some added genes, the salmon grows 2-6 times the size of a normal Atlantic salmon in half the time, promising some respite for the planet’s heavily taxed natural fish stocks, a third of which are near extinction or exhaustion. Talking Points Memo’s IdeaLab reports that a source close to the review process says that the FDA’s environmental impact statement, which looks at what effect the salmon will have on the environment and seems to be favorable, has been passed on to the White House’s Office of Management and Budget.
As always with genetically modified organisms, there are questions about how the salmon’s manufacturers plan to keep its genes from getting loose in the environment. AquaBounty has developed a way to make the fish sterile, which would make spreading their genes quite tricky. At the moment, however, it only works on 98% of the salmon. Additionally, the company is only seeking approval for growing the fish in large, land-locked tanks with double-thick walls. While giant nets teeming with fish in the middle of the ocean are a sight more commonly associated with aquaculture, inland tanks make the risk of modified fish escaping much smaller.
What’s the News: Hemophilia is perhaps best known as a disease of nineteenth-century royalty (specifically, of the oft-intermarried Hapsburgs), but it has evaded our efforts at a cure for thousands of years. And its effects are gruesome: mutations in the gene for a crucial clotting factor mean that victims can rapidly bleed to death from even small cuts.
Now, researchers working with hemophiliac mice have demonstrated a simple and apparently safe technique to swap in a functioning gene, giving hope for a future respite for sufferers of the disease.
Selfish genes could help destroy mosquitoes’ ability to carry malaria.
What’s the News: Many scientists have played with the idea of creating a genetically modified mosquito that won’t transmit malaria, which kills about 850,000 people a year, and releasing it into the wild. But in the face of the millions of mosquitoes out there that do ferry malaria around, how would the trait spread fast enough to make a difference?
Now, scientists have developed a way to cause a “selfish” gene to spread to more than half of a mosquito population over just a few generations, suggesting a method to quickly and broadly disrupt genes required for carrying malaria.
Swapping chromosomes among eggs could keep
embryos from inheriting genetic diseases.
What’s the News: Babies with three parents and fewer genetic diseases might soon be possible: A UK national health panel has found that techniques for swapping chromosomes between eggs so offspring don’t inherit disease-causing mutations from their mother’s mitochondria are not dangerous. The techniques, which have been tested in mice, monkeys, and human cells, still need to be studied more before making the transfer to the clinic, though, and as with all genetic engineering techniques, there’s a complex ethical maze ahead of researchers.
Swarms of genetically modified mosquitoes? This isn’t science fiction: The Malaysian government announced earlier this week that it unleashed 6,000 genetically modified (GM) skeeters into a forest as part of a plan to fight dengue fever, a potentially fatal affliction that can affect up to 100 million people each year.
The news appears to have caught the Malaysian media and public by surprise; many recent news stories reported that the study had been postponed after intense protests. As recently as 17 January, the Consumers’ Association of Penang and Sahabat Alam Malaysia, two groups opposing the use of GM insects, called on the National Biosafety Board to revoke its approval for the study. Scientists, too, were under the impression that the work had yet to begin, says medical entomologist Bart Knols of the University of Amsterdam. A 24 January blog post by Mark Benedict, a consultant at the Centers for Disease Control and Prevention in Atlanta who monitors the field closely, mentioned that the Malaysian study was “planned.” [ScienceNOW]
The study itself included the release of 12,000 male mosquitoes in total: 6,000 unaltered and 6,000 GM Aedes aegypti mosquitoes. The goal was to track how well the two types survived and how far they spread. U.K. biotech firm Oxitec created the modified mosquitoes, which don’t produce viable offspring. Researchers hope that if these altered males mate with wild females, it will bring the overall mosquito population down. The strategy has been tried once before in the Grand Cayman Islands, and results from that experiment are due to be published soon.