Robert Brucker grew up in rural Ohio, where farmers depend on herbicides to protect crops. Now in his lab in the Microbial Sciences Initiative at the Rowland Institute of Harvard, he studies how agrochemicals affect insects over multiple generations.“It’s important to recognize that the pesticides and herbicides we use are essential for our food security, and that following best practice in pest management is an essential part of life,” said Brucker, who is a Rowland fellow. “But now that we’re starting to understand the role of microbes in health, it’s time to look carefully at the impact these compounds have not only on cytotoxicity, but also on the microbiomes of pollinators and even ourselves.”In his latest study, published in Cell Host & Microbe, Brucker investigated the effects of atrazine, a common herbicide with comparatively low toxicity, on the microbes living in the guts of wasps. The study demonstrates that resistance to multiple pesticides can arise in a population exposed to low concentrations of atrazine, that the microbiome facilitates this resistance, and that it provides resistance against other pesticides to which the host animal has never been exposed.The discovery has important implications for the way the biological risks of agrochemicals are assessed.All animals have gut microbes that aid digestion and affect many other functions, including immunity and energy production. But experimental evolution studies into the impact of xenobiotics like atrazine on gut microbiomes is new. Brucker and his team focused on the gut of Nasonia vitripennis, a wasp commonly used as a model species for studying bees and other insects.Robert Brucker (pictured) investigated the effects of atrazine, a common herbicide, on the microbes living in the guts of wasps. Courtesy of Robert Brucker/Rowland Institute“We chose atrazine because it’s widely used for corn crops, and is considered to be safe to most animals: Up to 3 [parts per billion, or ppb] is allowable in drinking water. One of the first things we did was evaluate whether it was even toxic to our wasps — we had no reason to think it would be” at lower doses, said Brucker.The team exposed the insects to the same concentration of atrazine encountered by pollinators in newly sprayed agricultural fields and streams (300 ppb). That exposure changed the wasp’s microbiome diversity, causing a shift in bacterial populations that persisted across successive generations — even in offspring that were not exposed to atrazine.“The big surprise was that one exposure, even at a nontoxic level, was enough to cause a heritable change in the microbial community,” said Brucker.The atrazine-exposed wasps also had an increased tolerance of the herbicide glyphosate, even though they had never been exposed to the compound. Brucker and his colleagues found that even after the risk of exposure had been removed, the change to the wasp microbiome persisted across generations, with unexpected consequences on the insect’s ability to break down herbicides and pesticides.“Pesticide resistance is something that agriculture scientists are continually looking to avoid, so this finding is important,” Brucker pointed out. “When the wasps were only exposed to only 30 ppb of atrazine, the effect over 36 generations was increased resistance.”After discovering that a single exposure of a xenobiotic can have lasting changes on the wasps’ microbiomes, the researchers screened a population of wild honeybees. Wild bees and other pollinators have been at risk of exposure to atrazine since the 1950s.,“I collected honeybees from my family’s farm in Ohio, where following all of our best practices for pest management has been helpful in keeping our family together,” said Brucker. “Like most corn fields, the area had been sprayed with atrazine. The bees’ microbiomes had bacterial genes that could degrade atrazine, and likely other xenobiotics — and those genes were nearly identical to what we observed in our laboratory wasps.”The genes could only be from the bees’ gut bacteria, as honeybee genomes do not have atrazine-metabolizing genes.It’s not clear whether the changes brought on by exposure have negative consequences for pollinators and people. What’s important, Brucker says, is that the repercussions of repeated exposure across generations on microbiome health are unknown. They could well involve host behavior, metabolic stress, immunocompetence, and host-microbiota regulation. So while the microbiome is not yet considered in standardized risk assessments, that could change.“Everyone feels strongly about protecting our pollinator species, so we may need to be mindful of our uses of xenobiotics in crop management,” said Brucker. “We need to understand multigenerational exposure better, and make host–microbiome interaction part of biorisk assessment in the future, especially in light of increasing xenobiotic exposure to humans, plants, animals, fungi, and bacteria across the globe.”There are a few years of experimental work ahead for Brucker and his team before they will have specific recommendations for incorporating microbiome studies into biorisk assessments. Another direction for the researchers is to use their new understanding of gut bacteria in Nasonia to develop probiotics for honeybees that aim to reduce multi-pesticide exposure risk.
Aurora, In.—Forecasters from the National Weather Service say a wedge of high pressure from the north will take over the weather pattern bringing cooler and drier conditions into the area. Little if any cold cover is expected so generally sunny skies are expected with highs in the 40’s & 50’s and lows in the 20’s & 30’s. The next probable rainfall is currently in the forecast for Monday night.For residents in flood recovery areas, several relief agencies are staffing a free hotline for debris removal and home cleanup for Indiana residents. This hotline will connect those impacted by flooding with reputable and vetted relief agencies. All services are free, but not guaranteed due to an overwhelming need for assistance. Indiana residents needing assistance may call 800-415-1954. The hotline will be active until Thursday, March 17.
Submit Brexit has once again dominated the UK headlines, with questions now being raised as to who may be replacing Theresa May as Prime Minister if she is to step down. With MPs set to convene in the House of Commons this evening to vote yet again on Theresa May’s deal, it appears that the country is more divided than ever. With over one million people taking to the streets of London to call for the Government to revoke Article 50, bookmakers have seen a flurry of votes suggesting that the public are in favour of either delaying or cancelling brexit all together.Sarbjit Bakhshi, Head of Political Markets at Smarkets, explained to SBC that the recent petition to revoke Article 50 – which is currently at over 5.9m signatures – demonstrates a wish to remain in the European Union.Markets initially suggested that the petition, despite being dismissed by Parliament earlier in the week, was expected to gain 6m signatures by 30 March. However, the market has since flipped, with the exchange implying that the petition will not receive as many signatures as expected.Bakhshi told SBC: “With time running out and no consensus in the House of Commons, a revocation of Article 50 would take the time pressure of Parliament and pave the way to a slower Brexit of remaining in the EU. “Theresa May may be gambling on the pressure, pushing parliamentarians to support her deal and leading to a Brexit in a couple of weeks. Without the pressure, this situation may never fully resolve.”But with further disruption in Parliament, Theresa May has promised MPs that if her deal is to pass in tonight’s vote, she will resign. This has opened up a competition as to who will replace May, with Michael Gove and Boris Johnson earmarked as the favourites.Bakhshi continued: “The last few days have had Michael Gove and Boris Johnson compete for top place in out market. With last traded prices at 18% for Johnson and Gove, the market can’t seem to resolve which one of them is more likely to get the top job, but what is clear is how far ahead they are of the competition with Dominic Raab in third place at 12%”Tonight’s vote, according to Commons Leader Andrea Leadsom “really is the last chance” to pass a deal, but with many Labour MPs expected to vote against the deal, it is beginning to look a lot like a “blindfold Brexit.” Whatever happens with Brexit, there will be a number of implications for the gambling industry with the racing Tripartite agreement under threat, and European-based operators moving their businesses elsewhere. Share Related Articles Bakhshi and Shaddick launch ‘Art of the Possible’ podcast tracking US 2020 developments August 10, 2020 BGC: Government must ‘act fast’ and extend furlough scheme August 11, 2020 Share Europol warns of ‘greater risk’ of match-fixing during pandemic August 7, 2020 StumbleUpon