But in recent decades many insects have genetically adapted to become less sensitive to the potency of insecticides. In Africa, where long-lasting insecticide-treated bed nets and indoor spraying are major weapons in the fight against malaria, many species of mosquitoes across the continent have developed insecticide resistance that reduces the efficacy of these key interventions. In certain areas climate change is expected to exacerbate these problems.

University of California San Diego biologists have now developed a method that reverses insecticide resistance using CRISPR/Cas9 technology. As described in Nature Communications, researchers Bhagyashree Kaduskar, Raja Kushwah and Professor Ethan Bier with the Tata Institute for Genetics and Society (TIGS) and their colleagues used the genetic editing tool to replace an insecticide-resistant gene in fruit flies with the normal insecticide-susceptible form, an achievement that could significantly reduce the amount of insecticides used.

“This technology also could be used to increase the proportion of a naturally occurring genetic variant in mosquitoes that renders them refractory to transmission or malarial parasites,” said Bier, a professor of Cell and Developmental Biology in UC San Diego’s Division of Biological Sciences and senior author of the paper.

The researchers used a modified type of gene-drive, a technology that uses CRISPR/Cas9 to cut genomes at targeted sites, to spread specific genes throughout a population. As one parent transmits genetic elements to their offspring, the Cas9 protein cuts the chromosome from the other parent at the corresponding site and the genetic information is copied into that location so that all offspring inherit the genetic trait. The new gene-drive includes an add-on that Bier and his colleagues previously engineered to bias the inheritance of simple genetic variants (also known as alleles) by also at the same time cutting an undesired genetic variant (e.g., insecticide resistant) and replacing it with the preferred variant (e.g., insecticide susceptible).

In the new study, the researchers employed this “allelic drive” strategy to restore genetic susceptibility to insecticides, similar to insects in the wild prior to their having developed resistance. They focused on an insect protein known as the voltage-gated sodium channel (VGSC) which is a target for a widely used class of insecticides. Resistance to these insecticides, often called the knockdown resistance, or “kdr,” results from mutations in the vgsc gene that no longer permit the insecticide to bind to its VGSC protein target. The authors replaced a resistant kdr mutation with its normal natural counterpart that is susceptible to insecticides.

Starting with a population consisting of 83% kdr (resistant) alleles and 17% normal alleles (insecticide susceptible), the allelic drive system inverted that proportion to 13% resistant and 87% wild-type in 10 generations. Bier also notes that adaptions conferring insecticide resistance come with an evolutionary cost, making those insects less fit in a Darwinian sense. Thus pairing the gene drive with the selective advantage of the more fit wild-type genetic variant results in a highly efficient and cooperative system, he says.

Similar allelic drive systems could be developed in other insects, including mosquitoes. This proof-of-principle adds a new method to pest- and vector-control toolboxes since it could be used in combination with other strategies to improve insecticide-based or parasite-reducing measures to drive down the spread of malaria.

“Through these allelic replacement strategies, it should be possible to achieve the same degree of pest control with far less application of insecticides,” said Bier. “It also should be possible to design self-eliminating versions of allelic drives that are programmed to act only transiently in a population to increase the relative frequency of a desired allele and then disappear. Such locally acting allelic drives could be reapplied as necessary to increase the abundance of a naturally occurring preferred trait with the ultimate endpoint being no GMO left in the environment.”

“An exciting possibility is to use allelic drives to introduce novel versions of the VGSC that are even more sensitive to insecticides than wild-type VGSCs,” suggested Craig Montell (UC Santa Barbara), a co-author on this study. “This could potentially allow even lower levels of insecticides to be introduced into the environment to control pests and disease vectors.”

The study’s authors are: Bhagyashree Kaduskar (UC San Diego and Tata Institute for Genetics and Society), Raja Babu Singh Kushwah (UC San Diego and Tata Institute for Genetics and Society), Ankush Auradkar (UC San Diego), Annabel Guichard (UC San Diego and Tata Institute for Genetics and Society), Menglin Li (UC Santa Barbara), Jared Bennett (UC Berkeley), Alison Henrique Ferreira Julio, John Marshall (UC Berkeley), Craig Montell (UC Santa Barbara) and Ethan Bier (UC San Diego and Tata Institute for Genetics and Society).

Story Source:

Materials provided by University of California – San Diego. Original written by Mario Aguilera. Note: Content may be edited for style and length.

The study appears in the journal Science Advances.

The researchers explored how primitive life may have originated on our planet from simple, non-living materials. They asked what properties define life as we know it and concluded that anything alive would have needed to collect and use energy, from sources such as the Sun or hydrothermal vents.

In molecular terms, this would mean that the ability to shuffle electrons was paramount to life. Since the best elements for electron transfer are metals (think standard electrical wires) and most biological activities are carried out by proteins, the researchers decided to explore the combination of the two — that is, proteins that bind metals.

They compared all existing protein structures that bind metals to establish any common features, based on the premise that these shared features were present in ancestral proteins and were diversified and passed down to create the range of proteins we see today.

Evolution of protein structures entails understanding how new folds arose from previously existing ones, so the researchers designed a computational method that found the vast majority of currently existing metal-binding proteins are somewhat similar regardless of the type of metal they bind to, the organism they come from or the functionality assigned to the protein as a whole.

“We saw that the metal-binding cores of existing proteins are indeed similar even though the proteins themselves may not be,” said the study’s lead author Yana Bromberg, a professor in the Department of Biochemistry and Microbiology at Rutgers University-New Brunswick. “We also saw that these metal-binding cores are often made up of repeated substructures, kind of like LEGO blocks. Curiously, these blocks were also found in other regions of the proteins, not just metal-binding cores, and in many other proteins that were not considered in our study. Our observation suggests that rearrangements of these little building blocks may have had a single or a small number of common ancestors and given rise to the whole range of proteins and their functions that are currently available — that is, to life as we know it.”

“We have very little information about how life arose on this planet, and our work contributes a previously unavailable explanation,” said Bromberg, whose research focuses on deciphering the DNA blueprints of life’s molecular machinery. “This explanation could also potentially contribute to our search for life on other planets and planetary bodies. Our finding of the specific structural building blocks is also possibly relevant for synthetic biology efforts, where scientists aim to construct specifically active proteins anew.”

The study, funded by NASA, also included researchers from the University of Buenos Aires.

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Materials provided by Rutgers University. Original written by John Cramer. Note: Content may be edited for style and length.

Hydrogen — especially carbon-free green hydrogen — has emerged as a promising clean energy carrier and storage option for renewable energy such as solar and wind. It adds no carbon emissions to the atmosphere, but currently is costly and complex to create.

One way to produce green hydrogen is electrochemical water splitting. This process involves running electricity through water in the presence of catalysts (reaction-enhancing substances) to yield hydrogen and oxygen.

Researchers at Georgia Institute of Technology and Georgia Tech Research Institute (GTRI) have developed a new water-splitting process and material that maximize the efficiency of producing green hydrogen, making it an affordable and accessible option for industrial partners that want to convert to green hydrogen for renewable energy storage instead of conventional, carbon-emitting hydrogen production from natural gas.

The Georgia Tech findings come as climate experts agree that hydrogen will be critical for the world’s top industrial sectors to achieve their net-zero emission goals. Last summer, the Biden Administration set a goal to reduce the cost of clean hydrogen by 80% in one decade. Dubbed the Hydrogen Shot, the Department of Energy-led initiative seeks to cut the cost of “clean” or green hydrogen to $1 per kilogram by 2030.

Scientists hope to replace natural gas and coal, currently used today for storing extra electric energy at the grid level, with green hydrogen because it doesn’t contribute to carbon emissions, making it a more environmentally friendly means for storing renewable electricity. The focus of their research is electrolysis, or the process of using electricity to split water into hydrogen and oxygen.

Less Costly, More Durable Materials

Georgia Tech’s research team hopes to make green hydrogen less costly and more durable using hybrid materials for the electrocatalyst. Today, the process relies on expensive noble metal components such as platinum and iridium, the preferred catalysts for producing hydrogen through electrolysis at scale. These elements are expensive and rare, which has stalled the move to replace gas for hydrogen-based power. In fact, green hydrogen accounted for less than 1% of annual hydrogen production in 2020, in large part because of this expense, according to market research firm Wood Mackenzie.

“Our work will decrease the use of those noble metals, increasing its activity as well as utilization options,” said study principal investigator Seung Woo Lee, associate professor in the George W. Woodruff School of Mechanical Engineering, and an expert on electrochemical energy storage and conversion systems.

In research published in the journals Applied Catalysis B: Environmental and Energy & Environmental Science, Lee and his team highlighted the interactions between metal nanoparticles and metal oxide to support design of high-performance hybrid catalysts.

“We designed a new class of catalyst where we came up with a better oxide substrate that uses less of the noble elements,” said Lee. “These hybrid catalysts showed superior performance for both oxygen and hydrogen (splitting).”

Nanometer-scale Analysis

Their work relied upon computation and modeling from research partner, the Korea Institute of Energy Research, and X-ray measurement from Kyungpook National University and Oregon State University, which leveraged the country’s synchrotron, a football-field-sized super x-ray.

“Using the X-ray, we can monitor the structural changes in the catalyst during the water-splitting process, at the nanometer scale,” explained Lee. “We can investigate their oxidation state or atomic configurations under operating conditions.”

Jinho Park, a research scientist at GTRI and a leading investigator of the research, said this research could help lower the barrier of equipment cost used in green hydrogen production. Besides developing hybrid catalysts, the researchers have finetuned the ability to control the catalysts’ shape as well as the interaction of metals. Key priorities were reducing the use of the catalyst in the system and at the same time, increasing its durability since the catalyst accounts for a major part of the equipment cost.

“We want to use this catalyst for a long time without degrading its performance,” he said. “Our research is not only focused on making the new catalyst, but also on understanding the reaction mechanics behind it. We believe that our efforts will help support fundamental understanding of the water splitting reaction on the catalysts and will provide significant insights to other researchers in this field,” Park said.

Catalyst Shape Matters

A key finding, according to Park, was the role of the catalyst’s shape in producing hydrogen. “The surface structure of the catalyst is very important to determine if it’s optimized for the hydrogen production. That’s why we try to control the shape of the catalyst as well as the interaction between the metals and the substrate material,” he said.

Park said some of the key applications positioned to benefit first include hydrogen stations for fuel cell electric vehicles, which today only operate in the state of California, and microgrids, a new community approach to designing and operating electric grids that rely on renewable-driven backup power.

While research is well underway to XYZ, the team is currently working with partners to explore new materials for efficient hydrogen production using artificial intelligence (AI).

Termites belong to the cockroach branch of the evolutionary tree. They split from their sister cockroach group at the end of the Jurassic period, around 150 to 170 million years ago. A popular theory suggests that, after this split, they very gradually got smaller, and continue to do so today. But this new research, published in Proceedings of the Royal Society B, concluded that they rapidly got smaller over a 20-million-year period, then their size stabilized. The researchers, who are from the Evolutionary Genomics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), claim that the difference in the results from their research compared to the original theory comes from including fossilized species.

Postdoctoral fellow, Dr. Nobuaki Mizumoto, from the OIST Unit originally arrived in Okinawa to study termite behavior. “I wanted to compare the behavior of different kinds of termite species from around the world,” he explained. “I was going to travel to various places and collect them.”

But COVID-19 and the resulting travel restrictions put an end to those plans. So, Dr. Mizumoto turned his focus towards studying something that didn’t require him to leave Okinawa — the evolution of the size of termites.

Termite size, represented by their head width, has been comprehensively measured by taxonomists over the course of the last hundred years. In the past, when researchers catalogued a termite individual, they measured the head width as it is a stable measurement that, unlike body weight, is not affected by sample preservation methods.

Since modern non-termite cockroaches are larger than their modern termite cousins, it’s previously been proposed that termites have been getting smaller since the split. The body size of insects is thought to correlate to the complexity of their society. Smaller insects mean that more individuals can fit in a space. More individuals mean that tasks can be split up and allows for different castes — such as workers and soldiers — to evolve. As termites are social cockroaches, this theory did make sense. However, it had never been robustly tested, until now.

“The theory was somewhat supported when we just looked at modern species,” explained Dr. Mizumoto. “But when we started to include fossil species, it fell through. Some fossil species that lived 100 million years ago were already pretty small, and the smallest species to ever exist that we know of is a fossil species that existed around 50 million years ago.”

“What’s more,” he continued. “The head width of the ancestor of all the living termite species was estimated around 2mm. Yes, that’s larger than nearly 80% of all living species but it’s still very much within the range.”

In total there are just over 3000 species of termites described. So, the study was robust, examining nearly half the described species. Of those, 1562 are still alive today, whereas 76 are fossilized species. The oldest species looked at lived around 130 million years ago. The head width of the smallest termite was around 0.5mm, and the largest, around 5mm.

“Our analysis revealed that there’s a huge variation between species,” concluded Dr. Mizumoto. “And this includes a lot of fluctuation. Some species are seeing a size reduction, whereas others are actually getting larger. It depends on the lineage. This research provides a really good base for starting to make these comparisons and learning about the evolution of sociality in termites.”

The researchers highlighted that, while many studies focus on the evolution of sociality, especially within social insects, they often focus on wasps, ants, and bees. Indeed, studies on termites are lacking in number by comparison.

“A comprehensive perspective of termites is really important,” explained Prof. Tom Bourguignon, principal investigator of OIST’s Evolutionary Genomics Unit and senior author of the paper. “Most termite research only focuses on the few species that are well-known pests. This research diversifies our understanding of termites.”

Still unanswered, though, are the questions of how fast the Earth cooled and how long it might take for this ongoing cooling to bring the aforementioned heat-driven processes to a halt.

One possible answer may lie in the thermal conductivity of the minerals that form the boundary between the Earth’s core and mantle.

This boundary layer is relevant because it is here that the viscous rock of the Earth’s mantle is in direct contact with the hot iron-nickel melt of the planet’s outer core. The temperature gradient between the two layers is very steep, so there is potentially a lot of heat flowing here. The boundary layer is formed mainly of the mineral bridgmanite. However, researchers have a hard time estimating how much heat this mineral conducts from the Earth’s core to the mantle because experimental verification is very difficult.

Now, ETH Professor Motohiko Murakami and his colleagues from Carnegie Institution for Science have developed a sophisticated measuring system that enables them to measure the thermal conductivity of bridgmanite in the laboratory, under the pressure and temperature conditions that prevail inside the Earth. For the measurements, they used a recently developed optical absorption measurement system in a diamond unit heated with a pulsed laser.

“This measurement system let us show that the thermal conductivity of bridgmanite is about 1.5 times higher than assumed,” Murakami says. This suggests that the heat flow from the core into the mantle is also higher than previously thought. Greater heat flow, in turn, increases mantle convection and accelerates the cooling of the Earth. This may cause plate tectonics, which is kept going by the convective motions of the mantle, to decelerate faster than researchers were expecting based on previous heat conduction values.

Murakami and his colleagues have also shown that rapid cooling of the mantle will change the stable mineral phases at the core-mantle boundary. When it cools, bridgmanite turns into the mineral post-perovskite. But as soon as post-perovskite appears at the core-mantle boundary and begins to dominate, the cooling of the mantle might indeed accelerate even further, the researchers estimate, since this mineral conducts heat even more efficiently than bridgmanite.

“Our results could give us a new perspective on the evolution of the Earth’s dynamics. They suggest that Earth, like the other rocky planets Mercury and Mars, is cooling and becoming inactive much faster than expected,” Murakami explains.

However, he cannot say how long it will take, for example, for convection currents in the mantle to stop. “We still don’t know enough about these kinds of events to pin down their timing.” To do that calls first for a better understanding of how mantle convection works in spatial and temporal terms. Moreover, scientists need to clarify how the decay of radioactive elements in the Earth’s interior — one of the main sources of heat — affects the dynamics of the mantle.

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Materials provided by ETH Zurich. Original written by Peter Rueegg. Note: Content may be edited for style and length.

But University of Cincinnati associate professor Nathan Morehouse and an international team of researchers led by Cynthia Tedore at the University of Hamburg found that one jumping spider might have little appreciation for its own vivid splendor.

Morehouse examined Saitis barbipes, a common jumping spider found in Europe and North Africa. Males have a furry red crown and legs. Their coloration seems to complement their elaborate courtship dances to woo discerning females.

“We assumed they were using color for communication. But we didn’t know if their visual system even allowed them to see those colors,” said David Outomuro, a UC postdoctoral researcher now at the University of Pittsburgh.

Outomuro was first co-author of the study with Mateusz Glenszczyk, a researcher from the University of Hamburg.

Biologists collected spiders in Slovenia for lab study in Germany and used microspectrophotometry at UC to identify photoreceptors sensitive to various light wavelengths or colors. Unexpectedly, they found no evidence of a red photoreceptor. Likewise, they looked for colored filters within the eye that might shift green sensitivity to red, but found none.

Instead, they identified patches on the spider that strongly absorb ultraviolet wavelengths to appear as bright “spider green” to other jumping spiders. The red colors that are so vivid to us likely appear no different than black markings to jumping spiders.

“It’s a bit of a head-scratcher what’s going on here,” professor Morehouse said. “We haven’t solved the mystery of what the red is doing.”

The study was published in the journal The Science of Nature.

Animals use color in all sorts of ways, including camouflage, warning potential predators of their toxicity, showing off to potential mates or intimidating rivals. But it’s not always apparent what bright colors might signify, Morehouse said.

“We spent a lot of time talking about it as a group. What else could it be? I feel there’s an interesting story behind the mystery,” he said.

The results were surprising, said senior author Tedore, a research associate at the University of Hamburg.

“Males have bold red and black coloration on their forward-facing body surfaces which they display during their courtship dances; whereas, females lack red coloration altogether,” she said. “This initially suggested to us that the red color must play some role in mate attraction.

“Instead, we found that red and black are perceived equivalently, or nearly so, by these spiders and that if red is perceived as different from black, it is perceived as a dark ‘spider green’ rather than red,” Tedore said.

The spider’s red and black colors might improve defensive camouflage, the study suggested.

“For predators with red vision, at natural viewing distances, the spider’s red and black color patches should blur together to become an intermediate orangish-brownish color, which would help the spider blend in with its leaf litter habitat better than all-black coloration would,” Tedore said.

Many colorful jumping spiders see red perfectly well. And paradoxically, some drab-colored spiders also have excellent color vision.

“We thought it would be a tidy project. Colorful spiders can see many colors,” researcher Outomuro said.

But this discovery, Morehouse said, is a reminder of how animals can sometimes perceive the world in ways far different from us. For example, sunscreen absorbs ultraviolet light extremely well, but we never notice because we can’t see that spectrum.

“If aliens were to study us, they might ask, ‘Why did they paint their bodies with strongly UV absorbing colors when they went on the beach?’ We have no perception of ultraviolet light, so we have no idea we’re creating these strong ultraviolet colors when we put sunscreen on,” Morehouse said.

Morehouse is director of UC’s new Institute for Research in Sensing, which examines the way we and other animals perceive the world.

“What does a wind turbine or a car window or a high-rise look like to a bird that might run into it?” he asked.

“We need to consider their perceptual worlds to coexist. But I also think it’s inherently fascinating to imagine our ways into the lives of animals that experience the world in a way that is completely alien to us.”