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New microscope technique reveals internal structure of live embryos

Published August 8, 2017
Research team
Research team

CHAMPAIGN, Ill. — University of Illinois researchers have developed a way to produce 3-D images of live embryos in cattle that could help determine embryo viability before in vitro fertilization in humans.

Infertility can be devastating for those who want children. Many seek treatment, and the cost of a single IVF cycle can be $20,000, making it desirable to succeed in as few attempts as possible. Advanced knowledge regarding the health of embryos could help physicians select those that are most likely to lead to successful pregnancies.

The new method, published in the journal Nature Communications, brought together electrical and computer engineering professor Gabriel Popescu and animal sciences professor Matthew Wheeler in a collaborative project through the Beckman Institute for Advanced Science and Technology at the U. of I.

Called gradient light interference microscopy, the method solves a challenge that other methods have struggled with – imaging thick, multicellular samples.

In many forms of traditional biomedical microscopy, light is shined through very thin slices of tissue to produce an image. Other methods use chemical or physical markers that allow the operator to find the specific object they are looking for within a thick sample, but those markers can be toxic to living tissue, Popescu said.

“When looking at thick samples with other methods, your image becomes washed out due to the light bouncing off of all surfaces in the sample,” said graduate student Mikhail Kandel, the co-lead author of the study. “It is like looking into a cloud.”

GLIM can probe deep into thick samples by controlling the path length over which light travels through the specimen. The technique allows the researchers to produce images from multiple depths that are then composited into a single 3-D image.

To demonstrate the new method, Popescu’s group joined forces with Wheeler and his team to examine cow embryos.

“One of the holy grails of embryology is finding a way to determine which embryos are most viable,” Wheeler said. “Having a noninvasive way to correlate to embryo viability is key; before GLIM, we were taking more of an educated guess.”

Those educated guesses are made by examining factors like the color of fluids inside the embryonic cells and the timing of development, among others, but there is no universal marker for determining embryo health, Wheeler said.

“This method lets us see the whole picture, like a three-dimensional model of the entire embryo at one time,” said Tan Nguyen, the other co-lead author of the study.

Choosing the healthiest embryo is not the end of the story, though. “The ultimate test will be to prove that we have picked a healthy embryo and that it has gone on to develop a live calf,” said Marcello Rubessa, a postdoctoral researcher and co-author of the study.

“Illinois has been performing in vitro studies with cows since the 1950s,” Wheeler said. “Having the resources made available through Gabriel’s research and the other resources at Beckman Institute have worked out to be a perfect-storm scenario.”

The team hopes to apply GLIM technology to human fertility research and treatment, as well as a range of different types of tissue research. Popescu plans to continue collaborating with other biomedical researchers and already has had success looking at thick samples of brain tissue in marine life for neuroscience studies. 

This research was supported by the National Science Foundation, the U. of I. Computational Science and Engineering fellowship and the U. of I. Yuen T. Lo Outstanding Research Award.

One step closer in explaining MS relapse during upper respiratory infection

Published August 8, 2017
Andrew Steelman
Andrew Steelman

URBANA, Ill. – For most of us, the flu is just the flu. We suffer through it for several days, and eventually bounce back. But for patients with multiple sclerosis (MS) and other neurological diseases, the flu can trigger a cascade of immune responses that result in a full-blown relapse of the disease. In a recent study from the University of Illinois, researchers shed light on what may be happening in the brains of MS patients during upper respiratory infections. 

“We know that when MS patients get upper respiratory infections, they’re at risk for relapse, but how that happens is not completely understood,” says Andrew Steelman, an assistant professor with appointments in the Department of Animal Sciences, the Neuroscience Program, and the Division of Nutritional Sciences at U of I. “A huge question is what causes relapse, and why immune cells all of a sudden want to go to the brain. Why don’t they go to the toe?”

Steelman and his team used a strain of laboratory mice that are genetically prone to developing an autoimmune attack of the brain and spinal cord. After the mice were exposed to influenza, the research team examined changes in the mice and their brains.

First, exposure to the flu did induce an MS-like symptoms in some of the mice, even though the virus itself was not found in the brain. “If you look at a population of MS patients that have symptoms of upper respiratory disease, between 27 and 42 percent will relapse within the first week or two,” Steelman says. “That’s actually the same incidence and timeframe we saw in our infected mice, although we thought it would be much higher given that most of the immune cells in this mouse strain are capable of attacking the brain.” Nevertheless, the team believes they are on the right track.

When they looked more closely, the researchers found an increase in glial activation in brains taken from influenza infected mice. For a long time, glia cells were considered the glue that holds neurons in place, but it turns out they do much more than that. Certain types of glia cells are involved in calling immune cells—in this case, neutrophils, monocytes, and T-cells—to the brain.

“When glia become activated, you start to see trafficking of immune cells from the blood to the brain. We think that, at least for MS patients, when glia become activated this is one of the initial triggers that causes immune cells to traffic to the brain. Once there, the immune cells attack myelin, the fatty sheaths surrounding axons, causing neurologic dysfunction,” Steelman explains.

Glia may be sending the signal to immune cells via molecules known as chemokines. The researchers found that one chemokine in particular, CXCL5, was elevated in the brains of mice infected with flu as well as in the cerebral spinal fluid of human MS patients during relapse. Another research group recently suggested CXCL5 could be used to predict relapse, strengthening Steelman’s confidence in his results.

Despite knowing more about how immune cells are called to the brain during an upper respiratory infection, the team still can’t explain why the immune system attacks the brain. But being able to identify a particular piece of the puzzle, such as CXCL5, could get the medical community closer to a drug intervention in the future. And there’s a lot of value in that.

“MS patients have one or two relapses a year; it’s thought that these relapses contribute to the progression of the disease,” Steelman explains. “If we can pinpoint what’s driving environmental factors such as infection to cause relapse, then maybe we can intervene when the patient has signs of sickness, like runny nose or fever. If we could inhibit relapse by 50 percent, we could theoretically prolong the time it takes for the patient to experience continual loss of function and dramatic disability.”

The article, “Influenza infection triggers disease in a genetic model of experimental autoimmune encephalomyelitis,” is published in the Proceedings of the National Academy of Sciences (PNAS). Authors Stephen Blackmore, Jessica Hernandez, Emily Ryder, and Michal Juda are students in Steelman’s research group. The work was supported by the National Multiple Sclerosis Society, USDA NIFA, and the University of Illinois.

Corn and soybean exports update

Published August 7, 2017

URBANA, Ill. - While market observers focus on the changing outlook for corn and soybean yields brought on by the shift in weather patterns over the last few weeks, export markets continue to reveal consumption information relevant to price formation during the current and subsequent marketing years. A University of Illinois agricultural economist explains that exports will play a significant role in determining prices in both corn and soybean markets moving forward.

“At 2,225 million bushels, the current USDA projection for corn exports during the 2016-17 marketing year appears attainable given cumulative exports to date and unshipped sales,” says Todd Hubbs. On August 4, the Census Bureau released export data for June and corn exports for the marketing year through June totaling 1,965 million bushels. A comparison of Census Bureau export numbers with weekly export inspections provided by the USDA shows the Census export total running around 42.5 million bushels ahead of export inspection totals through June.

Through August 3, cumulative export inspections for the 2016-17 marketing year totaled 2,119 million bushels. “If the difference between the two totals remained constant over the period, total exports for corn currently sit at 2,162 million bushels. For the four weeks remaining in the marketing year, export inspections need to average 15.7 million bushels per week to meet the USDA projection,” Hubbs says. “For the last three weeks of export inspection data, corn exports averaged 38.1 million bushels per week. While this pace looks promising, expectations should be tempered by the weak export sales data over the last three weeks in corn for the current marketing year.”

Net sales over the last three weeks ending July 27 averaged 7.8 million bushels for the current marketing year. Total outstanding sales for the current marketing year sit at 198 million bushels, which is well above the 63 million bushels required to reach the USDA projection, Hubbs adds.  “Currently, the USDA projections look attainable with the potential for 2016-17 marketing-year totals to exceed current projections.”

Current USDA projections for corn exports during the 2017-18 marketing year total 1,875 million bushels, 350 million bushels lower than current marketing-year projections. World import projections during the 2017-18 marketing year provided by the USDA on July 9 are 5,740 million bushels, up 348 million bushels over the current marketing-year estimates. “The increase in world imports is led by increases in the European Union, Mexico, and Southeast Asia,” Hubbs says. “Large corn crops in South America may mitigate U.S. corn exports. The large corn export totals for the United States last fall due to poor crops in South America do not appear to be feasible in the upcoming marketing year. Current export sales data give indications to support this idea.” As of July 27, corn outstanding sales for the 2017-18 marketing year sit at 174.7 million bushels, a 45 percent decrease in sales from the same time last year.

USDA projections for 2016-17 marketing-year soybean exports total 2,100 million bushels as of the July 9 reports. Census Bureau export estimates through June place soybean exports at 1,977 million bushels. Census Bureau export totals came in 46 million bushels larger than cumulative marketing-year export inspections over the same period, Hubbs says. “As of August 3, cumulative export inspections for the current marketing year totaled 2,024 million bushels. If the same difference in export pace through June is maintained, total soybean exports will be 2,070 million bushels. For the four weeks remaining in the current marketing year, 7.5 million bushels of soybean exports are required each week to meet the USDA projection. Over the last three weeks, export inspections of soybeans averaged 21.7 million bushels. As of July 27, total outstanding sales for the current marketing year totaled 219 million bushels, which is well above the estimated 30 million bushels required to meet the USDA projection.”

As of July 27, net export sales for the current marketing year averaged 9.9 million bushels during the previous three weeks. Current data suggest soybean exports may exceed the USDA projection for this marketing year.

The USDA forecasts soybean exports to be 2,185 million bushels in the 2017-18 marketing year. World import projections for soybeans during 2017-18 stand at 5,460 million bushels, a 220 million bushels increase over the current marketing year. Chinese imports of soybeans make up a large portion of this increase with 2017-18 soybean imports projected to increase 110 million bushels to 3,454 million bushels. Similar to corn exports, large South American soybean crops may mitigate U.S. soybean export levels during the 2017-18 marketing year. Through July 27, outstanding sales of U.S. soybeans for the 2017-18 marketing year total 235 million bushels, down 42 percent from the same time last year.

“Corn and soybean exports during the 2016-17 marketing year provided a strong market for consumption. Current estimates of export pace place both crops on track to meet or possibly exceed USDA projections during the current marketing year. Early signs of reduced export potential during the 2017-18 marketing year foretell the possibility of lower export totals in 2017-18, but it is still too early to draw solid conclusions,” Hubbs says. “The size of the 2017 crop in both the U.S. and South America go a long way in determining U.S. export potential next marketing year.”

News Source:

Todd Hubbs, 217-300-4688

Climate change may confuse plant dormancy cycles

Published August 7, 2017
D.K. Lee examines switchgrass
D.K. Lee examines switchgrass

URBANA, Ill. – Perennial plants in the Midwest are well attuned to their surroundings. They hunker down all winter in a dormant state, just waiting for a sign that it’s safe to unfurl their first tender leaves or flower buds. For many plants, the cue is a sustained warming trend, but day length also factors into the dormancy equation.

Day length is governed by our trip around the sun each year – that’s set in stone – but unusual temperature fluctuations are becoming more common as our climate is changing. So what happens to perennials when the sun tells them they should stay dormant, but warming soil tells them another story? A new study from the University of Illinois has some answers.   

Switchgrass and prairie cordgrass, both native perennial grasses grown for biomass, come out of dormancy when the soil warms up for a week or more, usually in April. As temperatures rise, stored carbohydrates in the plants’ rhizomes are converted into mobile forms to fuel growing tissues. If this happens during an unusually early thaw, new shoots could be killed and rhizomes could be left depleted when temperatures return to their normal range. The plant may not have enough oomph to produce new shoots later in spring, affecting biomass yield in agronomic settings or competitive ability in natural plant communities. 

To look at the interplay between soil temperature, day length, and dormancy in switchgrass and prairie cordgrass, D.K. Lee and his collaborators designed a study to trick the plants.

“We dug plants up from the field and brought them into warm greenhouses in Illinois and South Dakota every month from October through March,” says Lee, an agronomist in the Department of Crop Sciences at U of I. “The only lighting was the sun, so the plants had to react to the ambient photoperiod, or day length.”

The warm temperatures triggered plants to start growing, but some of them got confused by the short days after they emerged. “Plants collected from October to January woke up, then, ‘whoa!’ The days were much shorter than they normally are when they wake up. Especially in October, November, and December, day length keeps decreasing. It’s too short. The plants think it’s weird,” Lee explains.

So weird, in fact, that the plants reentered a kind of dormancy. New switchgrass shoots stopped growing, but stayed green and alive; the researchers referred to this as stagnation. But the new shoots that prairie cordgrass produced died back completely. “Cordgrass went back to sleep,” Lee says. “The temperature cue for breaking dormancy was overridden by the day length cue.”

Lee notes that the original intent for the study was to gather information for breeding purposes. “Often times, we are trying to make crosses between two different populations with two different flowering times,” he says. “We artificially try to control and synchronize flowering by altering day length. Here, we weren’t changing day length, but we still wanted to see what happened with flowering.” The plants were allowed to continue their growing cycle through flowering. For the most part, flowering happened when it normally would, as flowering tends to be controlled more by day length than temperature. 

Regardless of the original intent of the study, Lee keeps coming back to what his results say about potential effects of climate change on perennial plants. “We think of climate change as being a slow and steady process; it’s possible that evolution could keep up with a pace like that. But we’re seeing extreme and sudden temperature fluctuations. That’s what we’re worried about,” he says.

If perennial plants come out of dormancy during an early thaw and then get hit with a late frost, which is what happened in 2012 in Illinois, the crop for that year could be lost. Even though prairie cordgrass is known to be cold tolerant, if short days force it back into dormancy after emergence, it still may have lower yields.

Those are just the agronomic concerns. Lee reiterates that temperature fluctuations could have major consequences for perennial plants in natural ecosystems. “What would happen if all the perennials die off or produce less biomass one year because of an early warm spell? Would aggressive annual weeds take over? The perennial plant community might have a shock.”

The unknowns are why Lee plans to continue studying perennial plant responses to day length and temperature. “We still don’t really know what’s happening with the carbohydrate reserves as these plants just start to break dormancy. Even before we see shoots coming out, they’re metabolizing and mobilizing carbohydrates. That’s a big energy consumption process, and we need to learn more to be able to predict how they’ll cope with temperature and day length cues,” Lee says.

The article, “Growth and development of two perennial grasses in ambient light conditions during their natural dormant period,” is published in Crop Science. The article is authored by Jia Guo and D.K. Lee at U of I, Arvid Boe at South Dakota State University, and Do-Soon Kim, at Seoul National University. The work was supported by USDA NIFA, South Dakota State University Experimental Station, and the Korean Federation of Science and Technology Societies.

News Source:

D.K. Lee, 217-333-7736

Nature journaling

Published August 7, 2017

URBANA, Ill. – Nature journaling enhances the outdoor or garden experience, while building a more positive and personal connection with nature.

“I use nature journaling as a creative form of self-expression, but I find that it also promotes relaxation and calmness,” says Rhonda Ferree, horticulture educator with University of Illinois Extension.

Many people journal. In its most basic form, journaling is a daily record of news and events that happen in a person’s life. Writing down our day-to-day happenings saves that information in an organized manner and helps us remember it later. “I’ve been journaling since I was a teenager, and my family often enjoys reading my old entries, reminding us of fun family times,” Ferree says.

Nature journaling provides all this and much more. “We all intuitively know that being in nature makes us happy,” Ferree notes. In fact, research shows that spending just 20 minutes in nature can promote health and well-being. Journaling while surrounded by nature allows us to slow down and see the natural world from a different perspective.

Relaxing in nature provides mental and emotional clarity to express our private experiences, thoughts, and feelings. While doing this, we begin to relax, thus enhancing the outdoor experience even more. After all, have you ever stayed in a bad mood while surrounded by nature? Journaling takes that positive experience to a deeper level, and makes it last longer.

Journaling is not difficult to do. “You don’t have to write a magazine-quality short story, just write what you see and feel,” Ferree recommends. “Over time we all develop our own style that works for us.”

Although most people journal with pen and paper, there are no rules. Some people prefer to blog, scrapbook, tweet, or use a smart-device writing app. You could also express those same thoughts through music, art, pictures, videos, and more. Ferree says to be creative. “Adding sketches and pictures makes the nature journal even more meaningful,” she says.

There are many writing techniques to help inspire our nature journaling activity. Start with the facts by writing down the date, weather conditions, and journaling location. Then sketch or write down your observations of that place. What do you see? What does it remind you of? Does it make you wonder or ask questions?  

Naturalist John Muir said, “I draw and work in my nature journal for three reasons: to see, to remember, and to stimulate curiosity. The benefit of journaling is not limited to what you produce on the page; it is, rather, found in your experience and how you think along the way.”

For more writing ideas and prompts, visit Rhonda Ferree’s ILRiverHort blog at http://web.extension.illinois.edu/fmpt/. There, you will also find a few examples of Rhonda’s nature journal writings.

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