ASU researchers discover more than 100 viruses in honeybees

By identifying new viruses in honeybees, researchers hope to understand how viruses affect health and behavior in bee colonies

July 23, 2019

With bee populations on the decline, researchers have a growing interest in the viruses that may be affecting them. However, with the exception of a few well-known viruses, very little is known about virus populations in bees.

A team of researchers in Arizona State University’s School of Life Sciences, led by a collaboration between the labs of life sciences professors Arvind Varsani and Brian Smith, decided to change that by conducting the first ever mass genomic study on bee viruses. School of Life Sciences social insect research A team of School of Life Sciences and Biodesign researchers discovered more than 100 unique viruses in honeybee populations. Understanding these viruses could help bee researchers determine which are important and which are detrimental for colony health. Photo by Sandra Leander/ASU Download Full Image

In this new study, published in July in the scientific journal “Infections, Genetics and Evolution,” Simona Kraberger, an assistant research scientist in Varsani’s lab, and Chelsea Cook, a postdoctoral scholar in Smith’s lab, identified more than 100 unique viruses in two subspecies and two different castes of honeybees.

“It’s not beyond the realm of possibilities that even in different subspecies of bees or different castes of bees, that they would have different viruses because those bees are doing totally different things, they’re behaving in totally different ways, they are experiencing totally different worlds,” Cook said. “Nurse bees are inside the colonies. They’re interacting with just larvae and each other whereas foragers are very on their own, interacting with the outside world, visiting flowers. To think that those two jobs have the same viruses, it’s just not going to be true.”

Because nurse bees are secluded, staying in the hive and only interacting with other members of the colony, Kraberger and Cook predicted that foragers would contain many more viruses. However, that’s not what they found.

They discovered more than 100 unique viruses, belonging to three classes of viruses, the most prevalent of those being microviruses, which infect bacteria.

Of the 70 microviruses they found, nurses housed 56 while foragers had only 12. In addition, there was a big difference between the two subspecies as the Italian bees had 51 microviruses and New World Carniolan contained only 19.

But what does this mean? In short, that more research is needed.

“One could build on a variety of hypotheses and my hypothesis is that perhaps the best they can do in that system is actually immunize themselves so the more diverse set of viruses you have, the better the immunity you have to anything,” said Varsani, associate professor in the Biodesign Center for Fundamental and Applied Microbiomics. “So, in that context, if you want to be the closest to your young, then surely what you want to do is be as clean as possible, or immune as possible, so you aren’t shedding anything.”

School of Life Sciences social insect research

Nurse bees stay inside the hive and care for larvae while forager bees explore the environment collecting nectar. However, researchers discovered that nurse bees had many more viruses than foragers. Now, they aim to figure out why. Photo by Sandra Leander/ASU

Now that they’ve identified the viruses, the group has several questions to pursue. Are some of the viruses beneficial while others are harmful? Are certain viruses keeping others in check? Is having a large variety of viruses positive or negative?

Kraberger has been studying viruses in a variety of organisms from plants to big cats since her earning PhD and she said the variety of viruses in bees is as diverse as she’s seen.

But is the variety of viruses seen in the bees a reason why bees are perishing? Not necessarily.

“One thing I will say is that viruses, even though they have a bad rap, are not all bad,” Kraberger said. “Viruses are very important in the ecosystem, and though they are going to infect something, they are good or bad for one thing and not for another.”

For example, viruses modulate bacteria in your stomach to make sure that one doesn’t take over and cause an illness. Viruses regulate fungi that can wipe out plant species, and they help balance the carbon cycle in the ocean.

However, scientists have discovered only about 1% of the virus population, Varsani said, and typically, the viruses are only studied when they cause a severe illness.

Understanding how virus populations regulate bee health and behavior could be an important step in learning more about viruses because they have social networks most equivalent to those found in humans.

“Social insects are good indicators of high interaction so can we then start using them as models for interaction networks. So, if you want to look at spread of a disease within a social community, social insects are one of the best ways to study them for the ways things move around,” Varsani said. “Do they have certain tipping points where they are fine, but then a change could wipe out the population? What we have done is start mapping the landscape and we’ve just unfolded a small part of it. Now we need to get unfold the entire larger part and chart the entire territory of viruses and figure out what’s there.”

Melinda Weaver

Communications specialist, School of Life Sciences


ASU researcher makes light work of quantum computing

July 23, 2019

Yuji Zhao has made a career out of making electronics more efficient using light-based technology. This work and his exploration into the quantum photonics realm recently put him in the national spotlight.

Zhao, an assistant professor of electrical and computer engineering in the Ira A. Fulton Schools of Engineering at Arizona State University, was awarded the Presidential Early Career Award for Scientists and Engineers in July. Yuji Zhao Yuji Zhao, an assistant professor of electrical and computer engineering in the Ira A. Fulton Schools of Engineering at Arizona State University, in his lab, where he works on semiconductor materials and devices research. Zhao was recently awarded the prestigious Presidential Early Career Award for Scientists and Engineers, which recognizes promising early career researchers and leaders. Photo by Pete Zrioka/ASU Download Full Image

The award is considered the highest honor bestowed by the U.S. government upon outstanding engineers and scientists embarking on careers of promising research and leadership. He joined two additional 2019 PECASE Award recipients from ASU and more than 300 early career faculty from universities across the country who were awarded this honor.

“This is a great honor for myself and my research team,” Zhao said. “We are extremely thrilled to see our work being recognized and we will continue to keep up the good work. It is also a recognition for the world-class research that is being carried out at the School of Electrical, Computer and Energy Engineering and the Fulton Schools at ASU.”

READ MORE: ASU researcher makes quantum leaps in materials engineering

Quantum computing possibilities light up with photonics

The PECASE Award supports Zhao’s project to advance the fundamental sciences in quantum photonics. With $1 million in funding from the U.S. Army Research Office provided through the PECASE Award, Zhao and his research team will advance new scientific understandings to enable the development of a special computing chip called a photonic integrated circuit, or PIC. PICs use photons, or light, to perform complicated tasks rather than electrons, which are used in conventional integrated circuits, or ICs.

“We are developing the world’s first PIC that can produce optical frequency comb at ultraviolet to visible wavelengths,” Zhao said. “They will replace the conventional large and heavy desktop optical setups with tiny semiconductor chips, which will enable us to study new quantum phenomena at a much smaller scale (the nanoscale) with much higher precisions, and enable new applications in quantum computing and biomedical sensing.”

A frequency comb is a tool that uses lasers to emit pulses of light and measures properties of wavelengths of light, which look like the teeth of a comb.

Zhao is working on the five-year project, “On-Chip Frequency Comb Generation at Visible Wavelengths Using III-Nitride Photonic Integrated Circuits” with his doctoral students Hong Chen and Jingan Zhou. Collaborators on the project include ASU electrical and computer engineering Professor Cun-Zheng Ning and researchers from the University of Southern California and the University of California, Los Angeles.

A prolific early career leading gallium nitride research

Zhao is a prominent gallium nitride, or GaN, researcher who has earned approximately $5 million in funding from the Department of Energy Advanced Research Projects Agency-Energy, the Department of Defense, the National Science Foundation and NASA over the past few years for GaN and III-nitride semiconductor-related research. His efforts are laying the foundation for faster, more efficient and higher-powered electronics.

GaN is what is known as a wide-bandgap semiconductor material. Its material properties allow for semiconductor devices to be smaller and operate more efficiently at higher voltages, frequencies and temperatures than silicon-based semiconductor materials.

During his doctoral studies at the University of California, Santa Barbara, Zhao developed GaN light-emitting diodes and lasers with world-record efficiency, “which made significant impacts in the field of solid-state lighting and displays,” he said.

Since he joined ASU in 2014, he and his research group have been developing new GaN devices for power electronics, space missions and quantum photonics applications — progress that has led to more than 70 journal and conference research papers published in the past five years.

In 2016, Zhao was awarded the Fulton Schools’ first NASA Early Career Faculty Space Tech Research Grant, which supported his research to create high-temperature-resistant solar cells.

Zhao’s GaN work has also caught the attention of the U.S. Department of Energy for its applications in making power electronics — switches that convert electricity from one form to another to be used by chargers and electrical grids — more powerful, efficient and compact. For a $1.5 million project funded by the DOE Advanced Research Projects Agency-Energy’s PNDIODES program, Zhao was selected to address technological gaps in GaN doping, or adding impurities, a critical technical step to achieving high-performance GaN power devices.

His GaN and solar cell work also has been recognized for its benefits in applications out of this world. Zhao attended the 2017 NASA Tech Day as one of only three university faculty members invited to join NASA’s senior leadership to talk about space technology with U.S. Congress members in Washington, D.C. He explained how his GaN work enables solar technology to retain its performance in high temperatures, something that isn’t possible with silicon-based solar cells. This technology is especially useful for missions to the extremely hot planet Mercury.

Zhao also received the Science Foundation Arizona Bisgrove Scholar Award to support his proposal to develop “smart” LEDs that can heal wounds and even replace current Wi-Fi technology with “Li-Fi,” or light-based wireless communications with 10,000 times the bandwidth capacity.

That work, which was at the time a relatively untested area of photonics and LED research, has yielded 20 papers published in leading research journals and in the publications of international conferences.

The U.S. Department of Defense has also supported Zhao's work to counter weapons of mass destruction by using aluminum nitride to create transistors capable of withstanding high voltage and radiation damage.

Supporting the next generation of gallium nitride researchers

Zhao is also proud of the outstanding students and young researchers who have emerged from his research group. Those include graduate students who have been recognized for contributions to advances in GaN research. In spring 2019, Zhao’s first doctoral student, Houqiang Fu, earned the Fulton Schools’ 2019 Palais Outstanding Doctoral Student Award, ASU’s highest honor for recognizing exceptional electrical engineering doctoral students excelling in research and academics.

His second doctoral student, Zhijian Lu, went on to a successful academic career as an assistant professor at the Southern University of Science and Technology, China. Zhao’s visiting scholar, Xiaodong Zhang, is now an associate professor at the Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Science.

“At ASU, there is nothing that makes us more proud than to see our students being successful,” Zhao said.

After only five years into his own successful academic career, Zhao has already made great strides in his area of expertise. The PECASE Award demonstrates he is looking at a bright future as a research leader.

Monique Clement

Communications specialist, Ira A. Fulton Schools of Engineering