Tag Archive for: UCLA Life Sciences

You are here: Home / UCLA Life Sciences

Posts

Patricia J. Johnson

UCLA microbiologist Patricia J. Johnson elected to National Academy of Sciences

/in /by
Patricia J. Johnson

Patricia J. Johnson

Patricia J. Johnson, UCLA professor of microbiology, immunology and molecular genetics, was elected to the National Academy of Sciences in recognition of her “distinguished and continuing achievements in original research.”

Membership in the academy is one of the highest honors that a U.S. scientist can receive. Its members have included Albert Einstein, Thomas Edison, Orville Wright and Alexander Graham Bell. The academy today announced the election of 100 new members and 25 foreign associates.

“I am very honored to be include among the ranks of such distinguished scientists,” said Johnson, who has appointments in the David Geffen School of Medicine at UCLA and the division of life sciences in the UCLA College.

Research in Johnson’s laboratory focuses on the molecular and cellular biology of a single cellular parasite called Trichomonas vaginalis. This microbe is responsible for the most prevalent, non-viral, sexually transmitted infection worldwide and is the most common parasite found in the U.S. population. An estimated 275 million people worldwide have the parasite, including approximately 3.7 million in the United States. In 2014, the Centers for Disease Control and Prevention identified trichomoniasis, the infection caused by T. vaginalis, as one of the “neglected parasitic infections in the United States.”

Johnson said that beyond its medical importance, T. vaginalis is a fascinating organism for conducting research on the evolution of biological processes present in all eukaryotes, from microbes to humans. The parasite’s atypical properties offer possible chemotherapeutic targets and vaccine candidates, she said.

Her laboratory focuses on several aspects of trichomonad biology, including its evolution, regulation of gene expression, drug resistance, genomics and biological processes vital for human infection.

“Our interdisciplinary research program merges several specialties, including structural and cell biology, biochemistry, genomics, proteomics, bioinformatics, evolution and medical sciences,” she said. “In recent years, we have narrowed our focus to defining and explaining critical pathogenic mechanisms that allow T. vaginalis to establish and maintain an infection. These studies include identifying critical parasite cell surface molecules and secreted vesicles, as well as defining human immune responses to parasitic infection. We have also investigated a possible link between infection with T. vaginalis and prostate cancer.”

The National Academy of Sciences was established in 1863 by a congressional act of incorporation signed by Abraham Lincoln that calls on the academy to act as an official adviser to the federal government, upon request, in any matter of science or technology. The academy is a private organization of scientists and engineers dedicated to the furtherance of science and its use for the general welfare.

Divers survey submersible cages used to farm cobia off the coast of Puerto Rico. UCLA researchers conducted the first country-by-country evaluation of the potential for marine aquaculture under current policies and practices.

Will ocean seafood farming sink or swim? UCLA study evaluates its potential

/in /by
Divers survey submersible cages used to farm cobia off the coast of Puerto Rico. UCLA researchers conducted the first country-by-country evaluation of the potential for marine aquaculture under current policies and practices.

Divers survey submersible cages used to farm cobia off the coast of Puerto Rico. UCLA researchers conducted the first country-by-country evaluation of the potential for marine aquaculture under current policies and practices.

 

Seafood farming in the ocean — or marine aquaculture — is the fastest growing sector of the global food system, and it shows no sign of slowing. Open-ocean farms have vast space for expansion, and consumer demand continues to rise.

As with many young industries, there’s a lot to figure out, from underlying science and engineering to investment and regulations.

In a study published in the journal Marine Policy, UCLA researchers report that they have conducted the first country-by-country evaluation of the potential for marine aquaculture under current governance, policy and capital patterns. They discovered a patchwork of opportunities and pitfalls.

Peter Kareiva, one of the study’s authors and director of the UCLA Institute of the Environment and Sustainability, said sustainable food systems are an important part of the fight against climate change.

“Like many environmental scientists, I see marine aquaculture as the future food system for a carbon neutral world,” Kareiva said. “But whether we get that future and a healthy ocean depends on governance and regulations — and we all know how sketchy those can be at times.”

In 2017, Kareiva’s research found that a tiny fraction of the world’s oceans, farmed sustainably — just 0.015 percent — could satisfy the entire world’s fish demand.

The new study categorizes 144 countries into three groups based on their capacity for aquaculture growth in the industry: “goldilocks,” “potential at-risk” and “non-optimized producer.” The categories are based on quality of government institutions and regulations, potential for investment and how suitable the biological and physical environment are for farming seafood in the ocean.

Sixty-seven countries fell in the goldilocks category for either finfish or bivalves, like mussels and clams — meaning conditions there are favorable for marine aquaculture. According to lead author Ian Davies, who conducted research for the study at Kareiva’s UCLA lab, the industry could help address social challenges in these places.

“There is a lot of potential in food-insecure countries, including island states in the Pacific and Caribbean,” Davies said. “They have limited resources and quickly growing populations. But these are also the countries with the most productive waters in the world.”

Twenty-four countries were identified as non-optimized producers, which lack highly productive waters but still engage in aquaculture, usually because of better access to investment. This group includes countries around the Persian Gulf and Black Sea, South Korea, Italy, Canada and Norway.

Finally, the paper categorized 77 countries as potential at-risk. These countries have suitable waters but poor access to capital and unstable, corrupt or ineffective governance systems. Despite such problems, 16 are currently farming fish in the ocean, often harming ecosystems or causing other problems in the process. China is by far the largest producer of ocean-farmed seafood, owing to strong financial capacity and political will, but was found to have poor oversight — which could pose problems for the industry in the future.

“The more robust regulation you have, the more you can ensure the industry will be around for longer, and that it will be able to produce fish at a reasonable cost with minimal input,” Davies said. “There is a palpable feeling among planners, researchers and aquaculture operators that we have the ability to do this right before the industry gets too big. Let’s put the regulations in place.”

Ineffective regulation often leads to ecosystem damage. In the 1990s, there was a shrimp farming boom in Southeast Asia. Operations added too much shrimp and feed to mangroves, destroying many in the process. The impact was also felt by humans. Mangroves serve as barriers that reduce storm surge and flooding, and many small aquaculture operators quickly found themselves out of business. More recently, unregulated fish farming led to disease outbreaks in northern Vietnamese waters.

In other observations, the study found that while lack of regulation poses problems, so can regulation that is too burdensome. In Ireland the licensing process takes years, making it impossible for operators to qualify for European Union grants. There are other country-specific barriers, too. New Zealand is a goldilocks country, but opposition from local communities and vocal stakeholders, including fishermen, has slowed marine development.

China is the largest marine aquaculture producer by far, but its waters are only moderately good and its governance was listed as low quality. The industry has succeeded there because of political will and access to capital. China isn’t alone. Excluding outliers, the study notes, less suitable countries produce almost six times as much fish as optimal countries. Capital-driven aquaculture in less suitable waters carries the risk of being less effective and more damaging.

Marine aquaculture is seen as promising compared to high-polluting inland operations. The open ocean disperses its impact, leading to fewer environmental problems. Meanwhile, according to the United Nations, nearly 90 percent of the world’s marine stocks are depleted, with many fisheries on the verge of collapse. Sustainably farming oceans could allow wild populations to rebound while serving as a crucial source of protein and economic benefits to humans.

Photo of UCLA professor Kent Hill and graduate student Stephanie DeMarco

Scientists identify a key gene in the transmission of deadly African sleeping sickness

/in , /by
Photo of UCLA professor Kent Hill and graduate student Stephanie DeMarco

Research by UCLA professor Kent Hill and graduate student Stephanie DeMarco, as well as colleagues at the University of Bern, could lead to new approaches to treat African sleeping sickness.

 

Life scientists from UCLA and the University of Bern have identified a key gene in the transmission of African sleeping sickness — a severe disease transmitted by the bite of infected tsetse flies, which are common in sub-Saharan Africa.

The disease is fatal if untreated, as the parasite responsible moves from the bloodstream to the central nervous system. Tens of millions of people in 36 African countries are at risk. There is no vaccine, and conventional drug treatments, which include an arsenic derivative, are antiquated, not very effective and have severe side effects.

The research, published in the journal Nature Communications, could lead to new approaches to treat the disease. It also provides scientists with the first detailed understanding of how the parasite moves through the fly and what genes enable it to do so.

The tiny, single-celled parasite that causes African sleeping sickness in humans, and debilitating diseases in other mammals, is called Trypanosoma brucei, or T. brucei. To become infectious, the parasite must travel through tissues of the fly, from the midgut to the salivary gland — and then into the human or other animal, through a bite.

In the study, Stephanie DeMarco, a UCLA graduate student in molecular biology, and Sebastian Shaw, a graduate student at Switzerland’s University of Bern, worked with two sets of the T. brucei parasite. In one set, they made a mutation in one of the parasite’s genes, called phosphodiesterase-B1, or PDEB1.

Then, they infected 2,000 tsetse flies with some 20,000 parasites each — half of the flies received blood containing normal T. brucei parasites and the other half received blood with the mutated versions.

When tsetse flies drink infected blood, the parasites from the blood typically travel to the midgut and then into a tissue closer to the head, called the proventriculus, before moving on to the salivary glands.

But the researchers saw a striking difference in the proventriculus between the two sets of flies. Among the flies that received the normal parasites, those that had parasites in the gut also had parasites in the proventriculus; but among the 1,000 flies that received mutant T. brucei, only a single one that had parasites in the gut also had a parasite in the proventriculus.

“The normal parasites were able to get to the proventriculus just fine, but for the mutants, we saw only one lonely parasite swimming around,” DeMarco said. “That told us that phosphodiesterase-B1 is really important for the parasites to move from the fly midgut to the proventriculus.”

Shaw said, “When we saw the huge difference between the mutants and normal parasites, at first we couldn’t believe it.”

Kent Hill, a UCLA professor of microbiology, immunology and molecular genetics, and one of the study’s senior authors, said the findings also suggested that there must be a barrier preventing the mutants from getting from the midgut to the proventriculus.

To learn where that barrier is, the scientists made fluorescent parasites and fed the flies a fluorescent dye that stained different tissues in the fly different colors, enabling the researchers to track the parasites.

To go from the midgut to the proventriculus, the parasites have to cross the peritrophic matrix, a sheet-like structure produced by the proventriculus that protects the midgut.

“We found the normal parasites could get through the peritrophic matrix just fine, but the mutants were mostly stuck on one side of it,” DeMarco said.

That finding indicated that the peritrophic matrix was the barrier the scientists were looking for.

The research identifies for the first time the genes that enable the parasites to sense where they are and allow them to survive their journey in fly tissues; those mechanisms had not been understood well until now.

“We think the way the parasites perceive where they are may be similar in the tsetse flies and in mammals — including humans — as they go through barriers and tissues,” said co-senior author Isabel Roditi, a University of Bern professor. “If so, there could potentially be a new drug that might disrupt their ability to do that.”

The researchers also uncovered another clue to African sleeping sickness: In parasites with mutated PDEB1, there was a dramatic increase in the number of cyclic AMP molecules, signaling molecules that play an important role in the disease.

Normal parasites are social and coordinate their behavior, DeMarco said. But the research revealed that without PDEB1, the parasites have too much cyclic AMP in their cells and can’t communicate with one another.

“When Sebastian and Stephanie got rid of PDEB1, the parasites got flooded with cyclic AMP,” Hill said. “Then, when the signal came in telling the parasites, ‘You’re in the stomach and you need to move,’ they couldn’t hear the sound. That’s what we think the problem is for the mutant parasites.”

Hill said the new insights from the UCLA–Bern study could apply to other disease-causing parasites as well. For example, T. brucei parasites are related to parasites found in the U.S. and elsewhere that cause Chagas disease, in which parasites invade heart tissue, leading to inflammation and enlarged heart tissue, and in some cases, heart failure.

Hill’s research is funded by the National Institutes of Health’s National Institute of Allergy and Infectious Diseases and the National Institute of General Medical Sciences. Roditi’s research is funded by the Swiss National Science Foundation and the Howard Hughes Medical Institute.

Diagram of Vegetation density in California in 2011 versus 2014.

California ‘browning’ more in the south during droughts

/in /by
Diagram of Vegetation density in California in 2011 versus 2014.

Vegetation density in California, 2011 versus 2014, when the state was in the midst of a drought that had especially severe effects in the southern part of the state.

 

Like a climate chameleon, California turned brown during the 2012–16 drought, as vegetation dried or died off.

But the change wasn’t uniform. According to research from UCLA and Columbia University, large areas of the northern part of the state were not severely affected, while Southern California became much browner than usual.

“Southern California is more prone than the northern part of the state to getting severe droughts,” said UCLA climate scientist Glen MacDonald, one of the paper’s authors. “But that difference seems to be increasing.”

That means additional stress will be placed on wildlife ecosystems and resources that the approximately 24 million people living in Southern California need to survive, including energy, food and water supply.

The problem isn’t just a lack of precipitation. Hotter temperatures due to global warming — which accelerate evaporation and make drought effects worse — are playing play a major role in many locations, including Southern California and some parts of the Sierra Nevada.

One band of low-to-middle elevation forest in the western Sierra was hit particularly hard and showed drastic browning, MacDonald said. That area of the Sierra Nevada experienced a high concentration of tree deaths, which contributed to California’s overall loss of more than 129 million trees since 2010.

In contrast, some parts of California became greener — mostly at high elevations and in the far northwestern part of the state, where it’s cooler and moister.

The researchers examined satellite images dating back to 2000 and historical records dating to 1895. They combined that data with information about drought severity and vegetation indexes — which analyze imagery to determine how densely green a patch of land is.

The research was partially funded by UCLA’s Sustainable LA Grand Challenge, which seeks to develop informed strategies to transition L.A. County to 100 percent renewable energy, 100 percent local water and enhanced ecosystem health by 2050.

Lead author Chunyu Dong, who worked on the project as a UCLA postdoctoral researcher, said the findings reveal a century-long trend in Southern California toward a drier climate that won’t affect only plants, but also the lives of millions of people.

“The Southern California water shortage will be more severe in the coming decades, especially when we consider the population here is increasing quickly,” Dong said.

The changes also have implications for wildfires, he added. Additional dry vegetation and hotter, windy weather could lead to more large fires that are difficult to control.

That lines up with 2017 research by MacDonald, who used the natural climate record contained in ancient tree rings to understand how climate variability and droughts have changed over hundreds of years. That paper found that California is in an unprecedented scenario in which the climate has warmed at the same time that variations in temperature and precipitation have been magnified, supporting rapid plant growth in wet years and then drying in hot summers, which provides more fuel for wildfires.

The 2019 rainy season made California drought-free for the first time since 2011, greening the state and causing wildflower superblooms, even in deserts. But MacDonald said the relief could be short-lived.

“The one thing that seems to keep coming up is that we’ll have more swings in precipitation,” he said. “We’re going to have our seasonally dry summer and that fine fuel is going to dry out. If it’s a hot summer, conditions are ripe for wildfire. The worst thing we can possibly do is say we don’t have to worry about this anymore.”

How climate change and drought will reshape the state’s vegetation in the long term remains to be seen. Some coastal sage scrub and chaparral could be replaced by grasslands, and low-elevation shrubland and woodland might even replace some coniferous forest, MacDonald said, but more study is needed.

Photo of Shane Campbell-Staton

UCLA biology professor uses superheroes to help students sift fact from fiction

/in , , /by
Photo of Shane Campbell-Staton

Shane Campbell-Staton, shown in his UCLA office, says comic books offer a fantastical look at biological concepts.

While Shane Campbell-Staton was working on his dissertation at Harvard in 2013, he walked into a comic book store in Cambridge, Massachusetts, and saw a comic in which Superman fought Muhammad Ali. That was the first comic book he ever bought.

An evolutionary biologist, he spent his days writing about the evolution of a small green lizard that adapted from a warm, sub-tropical environment to the cold winters of Tennessee, North Carolina and Oklahoma. Before going to sleep, he read the comic book as a guilty pleasure.

“Pitting the peak of human performance in Muhammad Ali against the peak of science fiction performance in the Man of Steel, in a ring with gloves on, I had to see how that fight ended,” Campbell-Staton said. (He refuses to spoil the ending by saying who won.)

Campbell-Staton became curious about other comic book universes, and returned to buy a couple of other superhero comics, which he also read before falling asleep. He started to have strange dreams that combined the biology he was thinking about with the comic books he was reading. He had a dream about the Flash – the fastest person in the world whose super speed is coupled with superhuman reflexes – running faster than a bullet. Campbell-Staton woke up thinking about muscle fiber, friction and metabolism — things that fuel a body.

“Science fiction and comic books are a really good way of approaching classic questions in biology from a different angle,” said Campbell-Staton, a UCLA assistant professor of ecology and evolutionary biology, whose research focuses on how reptiles and other animal species adapt to extreme environments, and the physiology, biology and evolution behind that process. “Comic books offer a fantastical look at the same concepts.”

Campbell-Staton started his popular Biology of Superheroes podcast in late 2017, which was a top 20 iTunes science and medicine podcast this January.

This quarter he is teaching a new “Biology of Superheroes” course for juniors and seniors in the life sciences. He uses superheroes such as Batman, Captain America, Black Panther and Wonder Woman, as well as Jurassic Park and zombies, to teach his students the biology of aging, genetics, evolution, genetic engineering, biotechnology, artificial intelligence, the ethics of reviving extinct species, parallel universes, intelligent alien life and how biology shapes modern society.

Photo of Shane Campbell-Staton giving a lecture to students.

Shane Campbell-Staton teaches his “Biology of Superheroes” course at UCLA.

Students read peer-reviewed research journal articles, chapters from science books and comic books. They can create their own science fiction or superhero podcast for their final project, or write a paper or a superhero short novel. Campbell-Staton said he would like to include some of their podcast material on his podcast.

Campbell-Staton said he wants to push students to think about biology in ways they typically would not.

“Regardless of whether these students go into medicine, research, politics, or other fields, my job is to help them sift fact from fiction,” Campbell-Staton said. “If you can sift fact from fiction in Spider-Man, that is a training ground for asking questions about what is true, what is not, and how to tell one from the other when it comes to complex ideas they will confront later in their lives.”

His students agree.

“Usually, we learn the biology of plants and animals. This class is refreshing and cool,” Fayt Sarreal said.

Student Andy Duong said Campbell-Staton cleverly weaves science into the superhero discussions in a creative and engaging way.

In a recent class session, Campbell-Staton raised a question posed by Harvard biologist Stephen Jay Gould (who died in 2002): If you replay the tape of evolution, will you repeatedly get the same results or different results?

The consensus among the students was the results would be different. One said the six-mile-wide asteroid that crashed to Earth 66 million years ago, wiping out the dinosaurs and approximately 75 percent of the world’s animal and plant species, might miss the Earth in an alternate scenario, and if so, the dinosaurs likely would still roam the Earth.

The 2018 movie, “Spider-Man: Into the Spider-Verse,” addresses this question with alternate universes. The character Peter Parker is Spider-Man in one universe, while Gwen Stacy is Spider-Woman in another universe. The same characters appear in different universes, but as a superhero in one universe, a normal person in a different universe, and a supervillain in another universe. The role of determinism in evolution is a lively, ongoing debate in evolutionary biology — one this movie explores through the lens of the multiverse, Campbell-Staton said. Gould argued that replaying the tape of life repeatedly would yield different results, likely not including humans.

An earlier class session covered whether elite athletes have to be extraordinarily gifted genetically. Campbell-Staton discussed specific gene mutations that influence endurance and muscle strength. He plans to teach the “Biology of Superheroes” each year in winter quarter.

When Campbell-Staton was in high school, he took a memorable course on myths and legends that delved into broader issues. “That always stuck with me as a unique and enjoyable learning experience that forced me to push myself,” he said.

40 UCLA scientists among world’s most influential scholars, based on citations

/in , /by

The researchers rank in the top 1 percent in their fields in producing widely cited studies, indicating that their work “has been repeatedly judged by their peers to be of notable significance and utility,” according to Clarivate.

Alumnus Morton La Kretz awarded the UCLA Medal, campus’s highest honor

/in , /by

“Morton’s leadership and philanthropy are testaments to his belief that the true measure of a life is not what you get, but what you give,” said UCLA Chancellor Gene Block at the medal ceremony.

For one grad and his dad a happy twist on like father, like son

/in , /by

Kevin thanks his mother’s persistence in pursuing her own education coupled with his father’s humble nature and drive to provide a safe and secure life for his family for molding him.

UCLA faculty voice: Separating children from parents at the border isn’t just cruel. It’s torture.

/in , /by

Children arriving at the U.S. border in search of asylum are frequently a particularly vulnerable population. In many cases fleeing violence and persecution, they also encounter hunger, illness and threats of physical harm along their hazardous journey to the border.

UCLA professors Paul Barber, Robert Wayne to enhance undergraduate STEM education

/in , /by

The program will provide year-long support for underrepresented minority pre-med students and offer an innovative curriculum that includes seminars, filmmaking and bench research focused on environmental variables contributing to health disparities.