With California’s produce sector feeling the crunch, lobby group Western Growers is fighting for sensible decisions from state and federal governments.
By analysing DNA extracted from the petrous bones of skulls of ancient Europeans, scientists have identified that these peoples remained intolerant to lactose (natural sugar in the milk of mammals) for 5,000 years after they adopted agricultural practices and 4,000 years after the onset of cheese-making among Central European Neolithic farmers.
The findings published online in the scientific journal Nature Communications (21 Oct) also suggest that major technological transitions in Central Europe between the Neolithic, Bronze Age and Iron Age were also associated with major changes in the genetics of these populations.
For the study, the international team of scientists examined nuclear ancient DNA extracted from thirteen individuals from burials from archaeological sites located in the Great Hungarian Plain, an area known to have been at the crossroads of major cultural transformations that shaped European prehistory. The skeletons sampled date from 5,700 BC (Early Neolithic) to 800 BC (Iron Age).
It took several years of experimentation with different bones of varying density and DNA preservation for the scientists to discover that the inner ear region of the petrous bone in the skull, which is the hardest bone and well protected from damage, is ideal for ancient DNA analysis in humans and any other mammals.
According to Professor Ron Pinhasi from the UCD Earth Institute and UCD School of Archaeology, University College Dublin, the joint senior author on the paper, “the high percentage DNA yield from the petrous bones exceeded those from other bones by up to 183-fold. This gave us anywhere between 12% and almost 90% human DNA in our samples compared to somewhere between 0% and 20% obtained from teeth, fingers and rib bones.”
For the first time, these exceptionally high percentage DNA yields from ancient remains made it possible for scientists to systematically analyse a series of skeletons from the same region and check for known genetic markers including lactose intolerance.
“Our findings show progression towards lighter skin pigmentation as hunter and gatherers and non-local farmers intermarried, but surprisingly no presence of increased lactose persistence or tolerance to lactose” adds Professor Pinhasi.
“This means that these ancient Europeans would have had domesticated animals like cows, goats and sheep, but they would not yet have genetically developed a tolerance for drinking large quantities of milk from mammals,” he says.
According to Professor Dan Bradley from the Smurfit Institute of Genetics, Trinity College Dublin, co-senior author on the paper, “our results also imply that the great changes in prehistoric technology including the adoption of farming, followed by the first use of the hard metals, bronze and then iron, were each associated with the substantial influx of new people. We can no longer believe these fundamental innovations were simply absorbed by existing populations in a sort of cultural osmosis.”
Wilberforce Ngugi is optimistic about human trials for vitamin-rich GM bananas. What do you think the initiative will mean for East Africa?
Nearly 100 severe hepatitis and liver failure illnesses — nearly half requiring hospitalization, including three transplants and one death — are raising new questions about the nation’s $ 32-billion-a-year supplements industry.
This comes only three months after the prestigious Annals of Internal Medicine found that all those vitamin and mineral supplements peddled by the industry are worthless if taken for preventing the occurrence or progression of chronic diseases.
All the recent liver damage was caused by a supplement called “OxyELITE Pro” sold by Texas-based USPlabs LLC, according to the U.S. Centers for Diseases Control and Prevention (CDC).
The supplement was recalled after it started crashing livers last May. While the U.S. Food and Drug Administration (FDA) was then able to get two substances, aegeline and 1,3-dimethylamylamine (DMAA), that were linked both to the illnesses and the fatality removed from the market, that’s about all FDA could do.
“The dietary supplement was recalled, but nothing has been done to prevent another supplement from causing organ failure or death,” Dr. Pieter Cohen writes in the New England Journal of Medicine. “Nor have any changes been made to improve the FDA’s ability to detect dangerous supplements.”
Cohen says FDA’s action on the liver-damaging supplement was a “delayed response” with “life-threatening consequences” because of “woefully inadequate” monitoring of the supplements.
Indeed, the most effective regulation of the supplements industry often comes not from FDA, but from the Federal Trade Commission (FTC) for the claims supplement companies make that cannot be justified by science. FTC, with jurisdiction over marketing, often forces supplement marketers to stop making outrageous claims about diet miracles or easy muscle building. FTC settlements often entirely remove brands from the market, but typically they come back in short order under another name.
Cohen says that, unlike drugs, which require FDA approval before they can be sold, “anything labeled as a dietary supplement is assumed to be safe until proven otherwise.” He says there are currently 85,000 different combinations of vitamins, minerals, botanicals, amino acids, probiotics and other supplement ingredients out there, and that the 20-year old federal law on supplements shields the industry from more effective oversight.
“The FDA is charged with the unenviable task of identifying and removing dangerous supplements only after they have caused harm,” Cohen says.
And he claims FDA has its work cut out for it because dangerous supplements are widely available. More than 500 supplements have already been found to be adulterated with drugs, stimulants, steroids, banned weight-loss medication and other harmful substances.
Cohen calls for a pre-market approval system to protect Americans from dangerous supplements and a better adverse event reporting system. He says FDA’s “Med Watch” reporting system for incidents involving drugs, medical devices and supplements is inadequate.
The supplements industry responded by saying that existing law is sufficient. Steve Mister, spokesman for the Council for Responsible Nutrition, said FDA requires 75 days notice for new supplement ingredients.
But Cohen says supplements with chemical compounds close to methamphetamine and amphetamine are being sold as “natural” by the supplements industry. His claim is backed up by recent news reports such as one this past October when a panel of international scientists found the body-building supplement called “Craze” contained a compound chemically similar to the illegal drug methamphetamine.
Craze was sold in candy grape, berry lemonade and piña colada flavors over the Internet and in retail stores like those that sell supplements and organic groceries.
U.S. Sens. Dick Durbin (D-IL) and Richard Blumenthal (D-CT) have introduced legislation to require supplement manufacturers to register products and provide FDA with more information about their potential adverse affects. Cohen says that, while the bill is an improvement, it would not improve FDA’s ability to detect and remove dangerous supplements from the market.
Grasshoppers are what they eat: New method to extract plant DNA from grasshopper guts sheds light on plant-insect interactions
Grasshoppers may be small, but the damages they are causing to the U.S. agriculture industry are anything but. Every year, they feed on crops and on rangelands needed for raising livestock, costing landowners millions of dollars. Although they pose a major threat, grasshopper populations play a positive role in cycling nutrients from decomposing plant matter back into the soil. A new method to investigate their feeding patterns could be the key to a better understanding of the impact of grasshoppers on plant communities.
“The main problem with current control methods is the damage done to non-target plant and insect species,” says University of Cincinnati researcher Alina Avanesyan, who developed the new protocol while studying grasshopper leaf tissue consumption. “Accurately determining the feeding preferences of grasshoppers can help us to understand the magnitude of plant damage, and consequently, whether or not control of grasshoppers is needed in a given area.”
The method recovers high-quality DNA of ingested plant tissue from grasshopper guts. This plant DNA offers valuable information about grasshopper diets because it holds more data than what can be observed by the naked eye. Scientists can use it to compare specific feeding patterns between different grasshopper species and uncover behaviors that might lead to intensive crop damage in certain areas. A detailed description of the dissection and DNA extraction, including a video illustrating the dissection technique, can be viewed in the February issue of Applications in Plant Sciences.
According to Avanesyan, “With this protocol, a researcher can focus on a variety of research questions, such as detecting plant-insect interactions, determining how long the food has been digested, estimating the prevalence of different plants in insect guts, exploring the sequence of multiple plant species consumed, and inferring feeding preferences.”
The protocol begins with a basic dissection kit used to isolate the grasshopper guts. A DNA extraction is then performed on the gut components, which results in a combination of grasshopper and plant DNA. Isolating the plant DNA involves a simple polymerase chain reaction, or PCR, which is used to amplify desired regions of genetic material for further research.
A major advantage of this method is that it can be completed in less than three hours and utilizes inexpensive laboratory equipment accessible to researchers with less funding. It also includes a new technique to divide the gut into sections, enabling researchers to track the step-by-step movement of plant matter through each gut compartment.
“We can follow plant food movement during its consumption, record the sequence of food digested (what plant was chosen to consume first) or the time needed for food digestion in each compartment, and ultimately better understand the insect food digestion process,” Avanesyan explains. “It opens doors to a completely different research area — insect physiology.”
To demonstrate the utility of the protocol, Avanesyan successfully amplified the DNA of a noncoding region of a plant chloroplast gene and performed multiple feeding trials. Results indicated that plant tissue could be detected up to 12 hours after ingestion in nymph M. differentialis and M. bivittatus grasshoppers and adult M. femurrubrum grasshoppers. For adult M. differentialis grasshoppers, which were the largest in size, plant tissue was detected up to 22 hours post-ingestion. This information lets researchers know how to time the dissection with feeding experiments.
Findings from the gut separation technique uncovered interesting details about M. differentialis grasshoppers. They often did not switch between grasses during feeding, but instead consumed different plant species sequentially.
The proposed protocol is an effective, relatively quick, and low-cost method of detecting plant DNA from a grasshopper gut and its different sections. Benefits extend far beyond grasshoppers, as it can be adapted to any insect herbivores of interest. New information obtained from ingested plant DNA could ultimately lead to more targeted and sustainable methods of managing insect populations, making the new gut DNA extraction method a valuable tool for the scientific community.
“It would be great to know whether there is a difference in digestibility between native and exotic plants, which are morphologically and physiologically similar,” says Avanesyan, who plans to continue to use the protocol to investigate plant defenses against insect herbivores.