This news was originally released in the University of Helsinki newsroom. Read the full story here.

In a new study led by Georgia Tech and University of Helsinki, researchers have discovered a mechanism steering the evolution of multicellular life.

Co-authored by the School of Biological Sciences’ Dung Lac, Anthony Burnetti, Ozan Bozdag, and Will Ratcliff, the study, “Proteostatic tuning underpins the evolution of novel multicellular traits”, was published in Science Advances this month, and uncovers how altered protein folding drives multicellular evolution.

The team’s research centers on the ongoing Multicellularity Long Term Evolution Experiment (MuLTEE) experiment, in which laboratory yeast are evolving novel multicellular functions, enabling researchers to investigate how these functions arise.

Among the most important multicellular innovations is the origin of robust bodies: over 3,000 generations, these ‘snowflake yeast’ started out weaker than gelatin but evolved to be as strong and tough as wood.

From an evolutionary perspective, this work highlights the power of non-genetic mechanisms in rapid evolutionary change. 

“We tend to focus on genetic change and were quite surprised to find such large changes in the behavior of chaperone proteins,” says Ratcliff. “This underscores how creative and unpredictable evolution can be when finding solutions to new problems, like building a tough body."

This press release is shared jointly with the UC Irvine newsroom.

The National Science Foundation (NSF) has awarded $15 million to an interdisciplinary team spanning 21 institutions across the country.

The six-year funding will support the Integrative Movement Sciences Institute (IMSI), an innovative group conducting groundbreaking research in the mechanics of muscle control during agile movements in changing environments.

NSF IMSI includes several key Georgia Tech researchers:

• Co-PI Simon Sponberg, Dunn Family Associate Professor in the School of Physics and School of Biological Sciences
• Lena Ting, professor and McCamish Foundation Distinguished Chair in Biomedical Engineering and co-director of the Neural Engineering Center
• Greg Sawicki, associate professor in the School of Mechanical Engineering and the School of Biological Sciences.

“To the best of our knowledge, this is the first US-based integrative center on the fundamental biology of muscle and movement that aims to bridge from the molecule to the whole animal to understand dynamic locomotion,” co-PI Sponberg says.

The research team also includes PI Monica Daley (UC Irvine), and additional Co-PIs Kiisa Nishikawa (Northern Arizona University), Jill McNitt-Gray (USC Dornsife College of Letters, Arts and Sciences), and Anne Silverman (Colorado School of Mines).

Leveraging expertise

“The Georgia Tech contingent will leverage the Institute's expertise in the multiscale biophysics of muscle, neuromechanics, integrative physiology and bio-robotic movement,” Sponberg says, “including the Institute’s expertise in fundamental muscle biology and movement technologies.”

The group will also collaborate with Tom Irving and Weikang Ma at the Argonne National Lab to leverage multiscale imaging, which will help connect the team’s understanding of the function of muscle at the nanoscale to the properties of that tissue during motion.

A central theme of the new Integrative Movement Sciences Institute will bridge fundamental discoveries about the biophysics and physiology of muscle and movement from insects to humans — research that Sponberg’s lab specializes in.

Last year, Sponberg also received a prestigious Curci grant to study coordinated movement in hawk moths. The team’s goal is to understand how muscle integrates with the rest of a body’s biology and the surrounding environment to allow animals and humans to move through so many varied environments. 

“Muscle is unlike any other tissue,” Sponberg says. “It enables movement in all animals and allows them to negotiate nearly every environment on this planet. For humans, it is the key piece of our physiology that translates our brain’s intentions into the movement that lets us get around in our world.

Creating models that can understand muscular control in dynamic, complex environments is vital, and could have applications spanning biotechnology, like building more dynamic robotics, and bioeconomy, creating avenues to develop new physical therapy and rehabilitation protocols.

“By integrating across scale and bringing to bear an interdisciplinary team of biologists, biophysicists, and bioengineers that span the scale from molecule to ecosystem, the new Integrative Movement Science Institute will create the next generation of muscle and movement models and experiments to understand locomotion in diverse settings,” Sponberg adds.

Funding for this research is provided by the National Science Foundation.

What’s in a name? A lot, actually.

For the scientific community, names and labels help organize the world’s organisms so they can be identified, studied, and regulated. But for bacteria, there has never been a reliable method to cohesively organize them into species and strains. It’s a problem, because bacteria are one of the most prevalent life forms, making up roughly 75% of all living species on Earth.

An international research team sought to overcome this challenge, which has long plagued scientists who study bacteria. Kostas Konstantinidis, Richard C. Tucker Professor in the School of Civil and Environmental Engineering at the Georgia Institute of Technology, co-led a study to investigate natural divisions in bacteria with a goal of determining a scientifically viable method for organizing them into species and strains. To do this, the researchers let the data show them the way.

Their research was published in the journal Nature Communications.

“While there is a working definition for species and strains, this is far from widely accepted in the scientific community,” Konstantinidis said. “This is because those classifications are based on humans’ standards that do not necessarily translate well to the patterns we see in the natural environment.”

For instance, he said, “If we were to classify primates using the same standards that are used to classify E. coli, then all primates — from lemurs to humans to chimpanzees — would belong to a single species.”

There are many reasons why a comprehensive organizing system has been hard to devise, but it often comes down to who gets the most attention and why. More scientific attention generally leads to those bacteria becoming more narrowly defined. For example, bacteria species that contain toxic strains have been extensively studied because of their associations with disease and health. This has been out of the necessity to differentiate harmful strains from harmless ones. Recent discoveries have shown, however, that even defining types of bacteria by their toxicity is unreliable.

“Despite the obvious, cornerstone importance of the concepts of species and strains for microbiology, these remain, nonetheless, ill-defined and confusing,” Konstantinidis said.

The research team collected bacteria from two salterns in Spain. Salterns are built structures in which seawater evaporates to form salt for consumption. They harbor diverse communities of microorganisms and are ideal locations to study bacteria in their natural environment. This is important for understanding diversity in populations because bacteria often undergo genetic changes when exposed in lab environments.

The team recovered and sequenced 138 random isolates of Salinibacter ruber bacteria from these salterns. To identify natural gaps in genetic diversity, the researchers then compared the isolates against themselves using a measurement known as average nucleotide identity (ANI) — a concept Konstantinidis developed early in his career. ANI is a robust measure of relatedness between any two genomes and is used to study relatedness among microorganisms and viruses, as well as animals. For instance, the ANI between humans and chimpanzees is about 98.7%.

The analysis confirmed the team’s previous observations that microbial species do exist and could be reliably described using ANI. They found that members of the same species of bacteria showed genetic relatedness typically ranging from 96 to 100% on the ANI scale, and generally less than 85% relatedness with members of other species.

The data revealed a natural gap in ANI values around 99.5% ANI within the Salinibacter ruber species that could be used to differentiate the species into its various strains. In a companion paper published in mBio, the flagship journal of the American Society for Microbiology, the team examined about 300 additional bacterial species based on 18,000 genomes that had been recently sequenced and become available in public databases. They observed similar diversity patterns in more than 95% of the species.

“We think this work expands the molecular toolbox for accurately describing important units of diversity at the species level and within species, and we believe it will benefit future microdiversity studies across clinical and environmental settings,” Konstantinidis said.

The team expects their research will be of interest to any professional working with bacteria, including evolutionary biologists, taxonomists, ecologists, environmental engineers, clinicians, bioinformaticians, regulatory agencies, and others. It is available online through Konstantinidis’ website and GitHub to facilitate access and use by scientific and regulatory communities.

“We hope that these communities will embrace the new results and methodologies for the more robust and reliable identification of species and strains they offer, compared to the current practice,” Konstantinidis said.

Note: Tomeu Viver and Ramon Rossello-Mora from the Mediterranean Institutes for Advanced Studies also led the research. Additional researchers from the Georgia Institute of Technology, University of Innsbruck, University of Pretoria, University of Las Palmas de Gran Canaria, University of the Balearic Islands, and the Max Planck Institute also contributed. 

Citation: Viver, T., Conrad, R.E., Rodriguez-R, L.M. et al. Towards estimating the number of strains that make up a natural bacterial population. Nat Commun 15, 544 (2024).

DOI: https://doi.org/10.1038/s41467-023-44622-z

Funding: Spanish Ministry of Science, Innovation and Universities, European Regional Development Fund, U.S. National Science Foundation.

Corals are foundational for ocean life. Known as the rainforests of the sea, they create habitats for 25% of all marine organisms, despite only covering less than 1% of the ocean’s area. 

Coral patches the width and height of basketball arenas used to be common throughout the world’s oceans. But due to numerous human-generated stresses and coral disease, which is known to be associated with ocean sediments, most of the world’s coral is gone.

“It’s like if all the pine trees in Georgia disappeared over a period of 30 to 40 years,” said Mark Hay, Regents’ Chair and the Harry and Anna Teasley Chair in Environmental Biology in the School of Biological Sciences at the Georgia Institute of Technology. “Just imagine how that affects biodiversity and ecosystems of the ocean.”

In first-of-its-kind research, Hay, along with research scientist Cody Clements, discovered a crucial missing element that plays a profound role in keeping coral healthy — an animal of overlooked importance known as a sea cucumber.

Read about how they figured it out at Georgia Tech Research News.