Tag: Life Sciences

New Studies Expose Coral Reef Crisis in Eilat

Written by AUFTAU on 28 May 2023. Posted in Newsroom.

Recent, unsettling studies conducted by Tel Aviv University have unveiled a deadly epidemic responsible for the widespread decimation of black sea urchins in the Mediterranean Sea and the Gulf of Eilat. Over the span of just a few months, the entire population of black sea urchins in Eilat was eradicated. For instance, within a few weeks, thousands of sea urchins inhabiting a site near the northern shore of the Gulf of Eilat perished. The severity of the epidemic is such that only skeletal remains of black urchins now occupy the site. Disturbingly, similar occurrences have been observed at various other locations in the Gulf of Eilat, as well as in neighboring countries including Jordan, Egypt, Saudi Arabia, Greece, and Turkey.

“At first we thought it was some kind of pollution or poisoning, or a local chemical spill (…) but when we examined additional sites in Eilat, Jordan, and Sinai, we quickly realized that this was not a local incident. All findings pointed to a rapidly spreading epidemic.” – Dr. Omri Bronstein.

Unveiling Deadly Epidemic

The studies were led by Dr. Omri Bronstein and PhD students Rotem Zirler, Lisa-Maria Schmidt, Gal Eviatar, and Lachan Roth from the School of Zoology, at The George S. Wise Faculty of Life Sciences, and The Steinhardt Museum of Natural History at Tel Aviv University. The papers were published in Frontiers in Marine science and Royal Society Open Science.

The researchers underscore the vital importance of sea urchins, particularly the long-spined Diadema setosum, as keystone species essential for the thriving equilibrium of coral reefs. They express a pressing concern, stating, “It must be understood that the threat to coral reefs is already at an all-time peak, and now a previously unknown variable has been added. This situation is unprecedented in the documented history of the Gulf of Eilat.”

According to the researchers’ hypothesis, the cause of the deadly epidemic can be attributed to a pathogenic ciliate parasite that has spread from the Mediterranean to the Red Sea. In response to the gravity of the situation, an urgent report outlining the current state has been submitted to the Israel Nature and Parks Authority, instigating deliberation on emergency measures to safeguard Israel’s coral reefs.

“Sea urchins in general, and Diadema setosum in particular, are considered key species essential for the healthy functioning of coral reefs. The sea urchins are the reef’s ‘gardeners’ – they feed on the algae and prevent them from taking over and suffocating the corals that compete with them for sunlight.” – Dr. Omri Bronstein

Dr. Omri Bronstein and a dying sea urchin

“At first we thought it was some kind of pollution or poisoning, or a local chemical spill, from the industry and hotels in the north of the Gulf of Eilat, but when we examined additional sites in Eilat, Jordan, and Sinai, we quickly realized that this was not a local incident,” explains Dr. Bronstein. “All findings pointed to a rapidly spreading epidemic. Similar reports are coming in from colleagues in Saudi Arabia. Even sea urchins that we grow for research purposes in our aquariums at the Interuniversity Institute, and sea urchins at the Underwater Observatory Marine Park in Eilat, contracted the disease and died, probably because the pathogen got in through the pumping systems.”

Dr. Bronstein describes it as a fast and violent death: “Within just two days a healthy sea urchin becomes a skeleton with massive tissue loss. While some corpses are washed ashore, most sea urchins are devoured while they are dying and unable to defend themselves, which could speed up contagion by the fish who prey on them.”

Invasion and Vanishing Species

In recent years, Dr. Bronstein’s research group has dedicated their efforts to the investigation of marine invasions, with a specific focus on the long-spined Diadema setosum. “Until recently, the black sea urchins with long spines, familiar to many of us, was one of the dominant species in Eilat’s coral reef,” reflects Dr. Bronstein. “Sea urchins in general, and Diadema setosum in particular, are considered key species essential for the healthy functioning of coral reefs. The sea urchins are the reef’s ‘gardeners’ – they feed on the algae and prevent them from taking over and suffocating the corals that compete with them for sunlight. Regrettably, these once-thriving sea urchins have vanished from the Gulf of Eilat and are quickly disappearing from constantly expanding parts of the Red Sea further to the south,” shares Dr. Bronstein with a sense of lament.

A dying urchin in the Mediterranean Sea (photo: Dr. Omri Bronstein)

Several months ago, Dr. Bronstein was alerted to the initial reports of widespread mortality by colleagues in Greece and Turkey, where the sea urchins had invaded, likely via the Suez Canal. “In 2006, the first sighting of this species of sea urchin occurred in the southern regions of Turkey,” Dr. Bronstein adds. This phenomenon, known as biological invasion, carries far-reaching ecological implications, pervasively affecting the eastern Mediterranean, particularly along Israel’s coastline. “We have been monitoring the dynamics of this species’ invasion in the Mediterranean since its first emergence,” he shares.

In 2016, they discovered the first Diadema setosum sea urchin along Israel’s Mediterranean coastline – a lone urchin sighted at Gordon Beach in Tel Aviv. For over a decade since the first discovery in Turkey, the Mediterranean populations of these sea urchins remained small and usually hidden. However, since 2018 the sea urchin population in the Mediterranean has been growing exponentially, reaching a state of population explosion – with giant populations of thousands and even tens of thousands found in Greece and Turkey.

“The window of opportunity for preserving a thriving population of this species in Eilat has regrettably closed. To establish a safeguard population, we must act without delay, by preserving healthy individuals from the Israeli Mediterranean before the encroaching disease from the north reaches this region.” Dr. Omri Bronstein

“However, during the course of our research, while scrutinizing the invasion of sea urchins in the Mediterranean, we began to receive reports on sudden extensive mortality,” says Dr. Bronstein. “While the extinction of an invasive species is supposedly not a bad thing, we must be aware of two major risks: Firstly, we don’t yet know how this mortality and its causes might impact local species in the Mediterranean. Secondly, and of far greater significance, the geographic proximity shared by the eastern Mediterranean and the Red Sea provides a potential conduit for the swift transmission of the pathogen into the Red Sea. As we feared and predicted, this is what appears to have happened.”

Dr. Bronstein and his research team (photo: courtesy of Dr. Omri Bronstein)

A Reminiscent Crisis

The massive loss of sea urchins reminded the TAU researchers of one of the most devastating events in marine ecology: the disappearance of the sea urchins in the Caribbean. Until 1983, the Caribbean coral reef thrived as a vibrant tropical ecosystem, much like the one in the Gulf of Eilat. But as the sea urchins vanished, the uncontrollable growth of algae took over, blocking sunlight from reaching the corals and forever altering the reef into a sea of algae.

Dr. Bronstein reveals, “Just last year, the Caribbean experienced another outbreak of the disease, resulting in the demise of the remaining urchin populations. However, unlike previous incidents, we now possess advanced scientific and technological resources to analyze the forensic evidence. Researchers from Cornell University successfully pinpointed the cause of mortality in the Caribbean: a pathogenic ciliate parasite. The identical pathology observed in the dying sea urchins of Greece, Turkey, and the Red Sea corroborates this finding.”

Dr. Bronstein’s pioneering research not only identified the unprecedented mass mortality of an invasive species in the Mediterranean but also shed light on the alarming decline of the widely prevalent sea urchin species, Diadema setosum. In a groundbreaking study, Dr. Bronstein issued a a warning that the epidemic plaguing the Mediterranean could extend its reach to the nearby Red Sea. Sadly, this cautionary prediction has become a disheartening reality.

Urgent Measures and Closing Window

“The gravity of the situation cannot be understated: the Red Sea is witnessing an alarming surge in mortality, surpassing the extent observed in the Mediterranean. Looming in the background is an ominous uncertainty: What is the exact cause of the sea urchin die-offs? Is it the same Caribbean pathogen or an entirely new and unfamiliar factor? Regardless, it is evident that this pathogen spreads through water, and we anticipate a rapid escalation of sickness and demise among the entire population of these sea urchins in both the Mediterranean and the Red Sea.”

“In my view, it is imperative that we swiftly establish a safeguard population for these sea urchins, ensuring the potential for their reintroduction into the wild. Similar to the approach taken with COVID-19, the trajectory of this epidemic remains uncertain. Will it eventually subside on its own, or persist for years, radically transforming coral reefs? However, unlike the COVID-19 pandemic, there are no available vaccines or treatments for the afflicted sea urchins. Hence, our efforts must be steadfastly directed towards prevention. The window of opportunity for preserving a thriving population of this species in Eilat has regrettably closed. To establish a safeguard population, we must act without delay, by preserving healthy individuals from the Israeli Mediterranean before the encroaching disease from the north reaches this region. While this is a complex undertaking, it is imperative if we aspire to secure the future of this unique species, which plays a critical role in the destiny of coral reefs,” concludes Dr. Bronstein.

Tel Aviv University Honors Nine Remarkable Individuals with Honorary Degrees

Written by AUFTAU on 21 May 2023. Posted in Newsroom.

In a festive ceremony held during the 2023 Board of Governors Meeting, Tel Aviv University awarded honorary degrees to 9 individuals, all of whom have had an exceptionally positive impact on the world. The honorary degrees were awarded by the Chairwoman of TAU’s Board of Governors, Dafna Meitar-Nechmad, President Prof. Ariel Porat and Rector Prof. Mark Steif.

Recipients include Morris Kahn, entrepreneur, philanthropist and founder of SpaceIL, who received the honour in recognition of his expansive philanthropic giving to causes including education, biomedical research, youth leadership, space exploration and the marine environment, as well as his commitment to Israeli science, as demonstrated through his generous support of diverse university- and hospital-based projects, including the 3D Cancer Printing Initiative at Tel Aviv University.

Other honorary degree recipients included Nobel Prize laureate Olga Tokarczuk, writer, activist and public intellectual, in recognition of her accomplishments as a world-renowned author and social activist, and her courageous efforts to secure Polish national recognition of crimes committed against Jews during the Second World War, as well as against refugees in the present day; Prof. Barbara Engelking, historian of Polish Jewry during the Holocaust, who was honoured in recognition of her pioneering contribution to Holocaust scholarship and her courageous determination to counter Holocaust distortion and expose the complexities of Polish-Jewish relations during the Second World War, regardless of personal cost.

Tamir Gilat was honoured for his heartfelt willingness, in his role as Chairman of the Israel Cancer Research Fund, to volunteer his time toward providing compassionate support to thousands of cancer sufferers and their families over the years; Sandra & Vlad Shmunis, entrepreneurs and philanthropists, received an honorary degree in recognition of their philanthropic spirit in supporting diverse important causes in Israel and the US through their family foundation, including Jewish values, young entrepreneurs, cancer research and Biblical archaeology.

WATCH: Highlights from the Honorary Degrees Conferment Ceremony, TAU’s Board of Governors Meeting 2023:

An honorary degree was also bestowed on Atallah Mansour in recognition of his immense contribution to civil, cultural, and democratic discourse in Israel over almost seven decades as a highly respected author and journalist; and on Prof. Antoine Compagnon, professor of French and comparative literature, College de France and Columbia University, who was honoured for his solidarity with the State of Israel during trying times, often in the face of public adversity.

Prof. Nicholas A. Peppas, chemical and biomedical engineer at the University of Texas at Austin, was awarded an honorary doctorate for his immeasurable influence as a leader and pacesetter in the fields of drug delivery, biomaterials and bio-nanotechnology over almost 50 years, as well as his interdisciplinary research approach, which blends molecular and cellular biology with materials engineering to produce next-generation biomedical systems and devices. Fellow scientist Prof. Pavel A. Pevzner, a computational biologist at University of California San Diego, was honoured for his standing as a world authority in computational biology and bioinformatics and his distinctive research approach that combines theoretical insights with the development of tools and practical applications for tackling real-world biological questions.

Finally, the George S. Wise Medal, the University’s highest honour, was awarded to Tharman Shanmugaratnam, Senior Minister and Coordinating Minister for Social Policies of Singapore, in recognition of his extraordinary public service record as an esteemed statesman and international economic leader.

Congratulations to all the recipients! Your accomplishments inspire us and make the world a better place.

International Study Reveals Genetic Link Between Modern Wine Grapes and Ancient Varieties

Written by AUFTAU on 4 May 2023. Posted in Newsroom.

International Study Reveals Genetic Link Between Modern Wine Grapes and Ancient Varieties.

A new study led by the paleogenetic laboratory of the Steinhardt Museum of Natural History at Tel Aviv University and the University of Haifa analyzed DNA from ancient local winegrape seeds discovered at archaeological excavations in the Negev. One seed was found to be almost identical to the Syriki variety used today to make high-quality red wine in Greece and Lebanon, while another seed is a relative of the white variety called Be’er, still growing in deserted vineyards in the dunes of Palmachim.

Exported to Europe

The genetic study was led by Dr. Pnina Cohen and Dr. Meirav Meiri of the paleogenetic lab at the Steinhardt Museum of Natural History at Tel Aviv University. The seeds were found at archaeological excavations led by Prof. Guy Bar-Oz from the School of Archaeology and Maritime Cultures at the University of Haifa, in collaboration with researchers from the Israel Antiquities Authority. Other participants included researchers from the University of Haifa, the Weizmann Institute, Bar-Ilan University, and research institutions in France, Denmark, and the UK. The paper was published in the leading scientific journal PNAS.

“The findings include large winepresses, jugs in which the exclusive wine, exported to Europe, was stored, and grape seeds preserved for more than a thousand years. This industry gradually declined following the Muslim conquest in the 7th century, since Islam forbids the consumption of wine.” – Prof. Guy Bar-Oz

“Archaeological excavations conducted in the Negev [in Israel] in recent years have revealed a flourishing wine industry from the Byzantine and early Arab periods (around the fourth to ninth centuries A.D.), especially at the sites of Shivta, Haluza, Avdat, and Nizana, which were large, thriving cities at the time,” says Prof. Guy Bar-Oz from the University of Haifa.

“The findings include large winepresses, jugs in which the exclusive wine, exported to Europe, was stored, and grape seeds preserved for more than a thousand years. This industry gradually declined following the Muslim conquest in the 7th century, since Islam forbids the consumption of wine.”

“The cultivation of winegrapes in the Negev was renewed only in modern times, in the state of Israel, mostly since the 1980s. This industry, however, relies mainly on winegrape varieties imported from Europe.”

Avdat Excavation (photo: Tali. Erickson-Gini and Scott Bucking)

Extracting DNA

One especially interesting finding was a large hoard of grape seeds, discovered on the floor of a sealed room at Avdat. The researchers explain that these seeds have been relatively well preserved thanks to protection from climatic phenomena such as extreme temperatures, flooding, or dehydration. To learn more about the seeds, in the hope of discovering which varieties they might belong to, the researchers prepared to extract their DNA in the paleogenetic lab.

The science of paleogenomic uses a range of advanced technologies to analyze ancient genomes, primarily from archaeological findings,” explains Dr. Meiri from the Steinhardt Museum of Natural History at Tel Aviv University. “Since the DNA molecule is very sensitive and disintegrates over time, especially under high temperatures, we usually get only small pieces of DNA, often in a poor state of preservation. To protect them we work under special conditions: the paleogenetic lab is an isolated clean laboratory, with positive air pressure that keeps contaminants out, and we enter it in sterilized ‘spacesuits’ familiar to everyone from the COVID pandemic.”

To begin with, the researchers looked for any organic matter remaining in the seeds. For this purpose, they used FTIR (Fourier-transform infrared spectroscopy) – a chemical technique applying infrared radiation to produce a light spectrum that identifies the sample’s content. Finding remnants of organic matter in 16 seeds, the researchers went on to extract DNA from these samples.

Ancient local winegrape seeds from Shivta, Israel (photo: Prof. Guy Bar-Oz, The University of Haifa)

Ancient Grapes – Still Around Today

The extracted DNA was sequenced, with an emphasis on about 10,000 genomic sites where variety-specific features are usually found, and the results were compared to databases of modern grapevines from around the world: In 11 samples, the quality of genetic material was too poor to allow any definite conclusions. Three of the remaining samples were identified as generally belonging to local varieties. Finally, the two samples of the highest quality, both from around 900 A.D., were identified as belonging to specific local varieties that still exist today.

The discovery was quite extraordinary:

One seed was found to belong to Syriki, a known Middle Eastern variety with a long history of cultivation in the Southern Levant and Crete, still used today to make high-quality red wine in Greece (where it is known to have arrived from the east) and in Lebanon. Since winegrapes are usually named after their place of origin, it is quite possible that the name Syriki is derived from Nahal Sorek, an important stream in the Judean Hills. Moreover, this variety may even appear in the Bible – in Jacob’s blessing to his son Judah: “He will tether his donkey to a vine, his colt to the choicest branch (soreka); he will wash his garments in wine, his robes in the blood of grapes (Genesis 49, 11); and perhaps also suggested in the giant cluster of grapes brought back by the men sent by Moses to explore the land: “When they reached the Valley of Eshkol (identified by some as Nahal Sorek), they cut off a branch bearing a single cluster of grapes. Two of them carried it on a pole between them” (Numbers 13, 23).
The other high-quality seed was identified as related to Be’er, a white winegrape variety still growing in the sands of Palmachim on Israel’s seashore, in remnants of vineyards probably abandoned in the mid- 20th century. For the first time ever, the researchers were able to use the genome of a grape seed to determine the color of the fruit, discovering that it was in fact a white grape – the oldest botanical specimen of a white variety ever identified. Be’er, a unique local variety, endemic to the land of Israel, is used today by the Barkan winery to make a special white wine of its own.

“The wonderful thing about paleogenetics is that sometimes, tiny items can tell a big story. This is exactly what happened in this study. With just a bit of DNA extracted from two grape seeds we were able to trace continuity in the local wine industry – from the Byzantine period, more than a thousand years ago, to the present day.” – Dr. Meirav Meiri

Tiny Items Tell a Big Story

“The wonderful thing about paleogenetics is that sometimes, tiny items can tell a big story,” says Dr. Meiri. “This is exactly what happened in this study. With just a bit of DNA extracted from two grape seeds we were able to trace continuity in the local wine industry – from the Byzantine period, more than a thousand years ago, to the present day.”

“We believe that our findings are also significant for Israel’s modern wine industry, which has been growing and thriving in recent decades. Today, most varieties grown here have been imported from Europe, so that the local conditions are not optimal for them. Local varieties can be more suitable for the local climate and soil, especially in the desert region of the Negev. Our study opens new paths for restoring and improving ancient local varieties, to create winegrapes that are more suitable for challenging climatic conditions such as high temperatures and little rainfall.”

Tiny items can tell a big story. Ancient winegrape seeds under a Microscope from Avdat (photo: Prof. Guy Bar-Oz, The University of Haifa)

Tel Aviv University Researchers Present New Treatment for Ovarian Cancer

Written by AUFTAU on 30 April 2023. Posted in Newsroom.

Ovarian cancer ranks fifth in cancer deaths among women, accounting for more deaths than any other cancer of the female reproductive system. In a study conducted at Tel Aviv University researchers used protein CKAP5 (cytoskeleton-associated protein) for the first time as a therapeutic target for RNA-based nanodrugs. After identifying a genetically unstable mutation resistant to both chemotherapy and immunotherapy in the tissues of ovarian cancer, the researchers targeted these cells with lipid nanoparticles containing RNA for silencing CKAP5 – causing the cells to collapse and achieving an 80% survival rate in animal models.

“The lipid nanoparticles developed by Prof. Peer enabled us for the first time to silence [the CKAP5] protein through targeted delivery of an RNA drug. We proved that CKAP5, a protein responsible for the cell’s stability, can be silenced, and that this procedure collapses and destroys the entire cancer cell.” – Dr. Sushmita Chatterjee

Targeted Delivery of RNA Drug

The breakthrough was achieved by a TAU research team led by Prof. Dan Peer of The Shmunis School of Biomedicine and Cancer Research, a global pioneer in the development of RNA-based drugs, Head of the Laboratory of Precision Nanomedicine, and TAU’s VP for R&D; and by Dr. Sushmita Chatterjee, post-doctoral student from India at Prof. Peer’s lab, in collaboration with Prof. David Sprinzak of The George S. Wise Faculty of Life Sciences and Prof. Ronen Zaidel-Bar of the Sackler Faculty of Medicine. The study was funded by the Rivkin Foundation for Ovarian Cancer Research and the Shmunis Family Foundation. The results were published in the leading scientific journal Science Advances.

“The protein CKAP5 has never been studied with relation to the fight against cancer, simply because there was no known way to silence it,” explains Dr. Chatterjee. “The lipid nanoparticles developed by Prof. Peer enabled us for the first time to silence this protein through targeted delivery of an RNA drug. We proved that CKAP5, a protein responsible for the cell’s stability, can be silenced, and that this procedure collapses and destroys the entire cancer cell.”

Prof. Dan Peer

“Something Like a Dominoes Game”

At the second stage of the study the researchers tested the new CKAP5-silencing RNA drug on 20 types of cancer. Some cancer cells proved more sensitive than others to this procedure. Cancers displaying high genetic instability, which are usually highly resistant to chemotherapy, were found to be especially sensitive to the silencing of CKAP5.

“As researchers, we are involved in something like a dominoes game: we always look for the one piece in the cancer’s structure that is so important, that if we pull it out the entire cell will collapse. CKAP5 is such a domino piece, and we are already working on more applications (…)” – Prof. Dan Peer

“All cancer cells are genetically unstable,” says Dr. Chatterjee. “Otherwise, they would be healthy, not cancerous. However, there are different levels of genetic instability. We found that cancer cells that are more unstable, are also more affected by damage to CKAP5. Our drug pushed them to their limit, and essentially destroyed their structure. Our idea was to turn the trait of genetic instability into a threat for these cells, by using RNA to silence the flawed protein. We demonstrated for the first time that CKAP5 can be used to kill cancer cells, and then observed the biological mechanism that causes the cancer cells to collapse in the protein’s absence.”

Equipped with these insights, the researchers tested the new drug in an animal model for ovarian cancer, achieving a survival rate of 80%.

“We chose ovarian cancer because it’s a good target,” explains Prof. Peer. “While highly resistant to both chemotherapy and immunotherapy, this type of cancer is very sensitive to the silencing of CKAP5. It should be emphasized that the CKAP5 protein is a new target in the fight against cancer. Targeting cell division is not new, but using RNA to target proteins that make up the cell’s skeleton (cytoskeleton) – this is a new approach and a new target that must be further investigated. As researchers, we are involved in something like a dominoes game: we always look for the one piece in the cancer’s structure that is so important, that if we pull it out the entire cell will collapse. CKAP5 is such a domino piece, and we are already working on more applications, this time in blood cancers.”

Bats Get “Pregnancy Brain” Too

Written by AUFTAU on 23 April 2023. Posted in Newsroom.

New study finds that pregnancy affects bats’ sensing capabilities.

“Pregnancy brain” – sometimes called “brain fog” or “mommy brain” – refers to a pregnant woman’s forgetfulness during and shortly after pregnancy. And there have indeed been several studies pointing to an impairment of the cognitive abilities of pregnant women. Apparently, the condition does not just affect us humans: a new Tel Aviv University study reveals that bats, too, experience a decline in their ability to hunt and orient in space during pregnancy.

This impairment stems from the fact that they produce about 20 percent fewer calls, the sounds that allow them to orient themselves using echolocation, on top of flying at a slower pace and at a lower altitude. The researchers highlight the fact that, to the best of their knowledge, this is the first evidence of pregnancy affecting mammals’ sensory abilities.

“When a bat makes fewer calls, it gathers less information about the environment, its chance of colliding with objects increases, and its chance of finding food decreases — and this is at a time when the bat needs extra food to sustain the fetus in its womb.” Prof. Yossi Yovel

Affecting Bats’ Safety and Hunting

The study was led by Mor Taub, a research assistant in the laboratory of Prof. Yossi Yovel, head of Tel Aviv University’s Sagol School of Neuroscience and faculty member of the School of Zoology at The George S. Wise Faculty of Life Sciences. The study’s findings were published in the journal BMC Biology.

Mor Taub explains: “At the peak of pregnancy, bats carry about 20 percent more than their normal body weight, and it is clear that this excess weight impacts their flying capacity. In this study, we wanted to check whether and to what extent pregnancy affects bats’ echolocation ability, their sonar.”

“Bats’ sonar is based on the emitting and receiving of strong and frequent sounds in order to map their surroundings. To make these sounds, bats, like us humans, need to transfer high-pressure air from the lungs through the vocal cords, or vocal membranes, which involves many muscles, such as the chest and diaphragm. We wanted to see if the excess weight from pregnancy affects the production of sounds.”

Prof. Yossi Yovel

To this end, Prof. Yovel and his colleagues taught bats to search for and land on a small landing pad in a flight room in the bat laboratory at Tel Aviv University’s Garden for Zoological Research. They recorded the echolocation of two groups: pregnant bats and non-pregnant bats. The researchers found that the rate at which the pregnant bats emitted sounds was significantly lower than that of the control group, with 20% greater intervals between each sound.

Prof. Yovel explains that “bats change the rate of the sounds they make in accordance with the level of difficulty of the task. The average rate is about ten calls per second, but when the bat lands, this rate can increase to 100 calls per second. The pregnant bats produced sounds at a rate of only about seven per second and flew a little slower and lower.”

“Obviously, this slowing down is likely to affect their hunting. When a bat makes fewer calls, it gathers less information about the environment, its chance of colliding with objects increases, and its chance of finding food decreases — and this is at a time when the bat needs extra food to sustain the fetus in its womb. In the second phase of the study, we used a computer simulation to simulate the effect of the decreased rate of calls on the bats’ performance, and indeed, we saw that the slowed rate makes it more difficult for the bats to locate prey.”

“This is the only evidence we found in the professional literature showing that pregnancy affects mammals’ sensory abilities.” – Mor Taub

Preserving the Vulnerable

The bats in the experiment were of the Kuhl’s pipistrelle species, tiny bats that weigh only about six grams (when they are not pregnant). These bats are very common in Israel, and feed mainly on mosquitoes. Despite their weight, bats can live for decades, and their pregnancies are therefore also relatively long, lasting about four months.

Previous studies conducted on other species of bats have shown that during pregnancy, bats tend to change their diets. To date, the assumption was that this change in diet was due to the bats’ difficulty in flying, but the current study raises the possibility that the change may also be due to their sensory difficulty in detecting certain types of prey.

“This is the only evidence we found in the professional literature showing that pregnancy affects mammals’ sensory abilities,” says Mor Taub. “We assume that there are similar cases in other species as well, but this is the first time that researchers have been able to measure and demonstrate the impairment empirically. Beyond the scientific interest, it is important to preserve mammal species in the wild, especially during pregnancy and newborn care, since animals are particularly vulnerable during this period.”

Plants Emit Sounds – Especially When Stressed

Written by AUFTAU on 1 April 2023. Posted in Newsroom.

In a world first, Tel Aviv University researchers record and analyze sounds distinctly emitted by plants.

Do you talk to your plants? While you may not be able to hear them, yaour plants could very well be chatting away as well (perhaps they are not such great listeners after all), and that’s especially true if they are having a bad day (did you forget to water them again?). For the first time in the world, TAU researchers recorded and analyzed sounds distinctly emitted by plants. The click-like sounds, resembling the popping of popcorn, are emitted at a volume similar to human speech, but at high frequencies, beyond the hearing range of the human ear. The researchers: “We found that plants usually emit sounds when they are under stress, and that each plant and each type of stress is associated with a specific identifiable sound. While imperceptible to the human ear, the sounds emitted by plants can probably be heard by various animals, such as bats, mice, and insects.”

“From previous studies we know that vibrometers attached to plants record vibrations, but do these vibrations also become airborne soundwaves – sounds that can be recorded from a distance? Our study addressed this question, which researchers have been debating for many years.” Prof. Lilach Hadany

Resolving Old Scientific Controversy

The study was led by Prof. Lilach Hadany from the School of Plant Sciences and Food Security at The George S. Wise Faculty of Life Sciences, together with Prof. Yossi Yovel, Head of the Sagol School of Neuroscience and faculty member at the School of Zoology and the Steinhardt Museum of Natural History, and research students Itzhak Khait and Ohad Lewin-Epstein, in collaboration with researchers from the Raymond and Beverly Sackler School of Mathematical Sciences, the Institute for Cereal Crops Research, and the Sagol School of Neuroscience – all at Tel Aviv University. The paper was published in the prestigious scientific journal Cell.

“From previous studies we know that vibrometers attached to plants record vibrations,” says Prof. Hadany. “But do these vibrations also become airborne soundwaves – sounds that can be recorded from a distance? Our study addressed this question, which researchers have been debating for many years.”

WATCH: Prof. Yossi Yovel and Prof. Lilach Hadany on their findings

At the first stage of the study the researchers placed plants in an acoustic box in a quiet, isolated basement with no background noise. Ultrasonic microphones recording sounds at frequencies of 20-250 kilohertz (the maximum frequency detected by a human adult is about 16 kilohertz) were set up at a distance of about 10cm from each plant. The study focused mainly on tomato and tobacco plants, but wheat, corn, cactus and henbit were also recorded.

“Our findings suggest that the world around us is full of plant sounds, and that these sounds contain information – for example about water scarcity or injury (…) We believe that humans can also utilize this information, given the right tools – such as sensors that tell growers when plants need watering.” – Prof. Lilach Hadany

Mapping Plants’ Complaints with AI

Before placing the plants in the acoustic box, the researchers subjected them to various treatments: some plants had not been watered for five days, in some the stem had been cut, and some were untouched. Prof. Hadany explains that their intention was to test whether the plants emit sounds, and whether these sounds are affected in any way by the plant’s condition: “Our recordings indicated that the plants in our experiment emitted sounds at frequencies of 40-80 kilohertz. Unstressed plants emitted less than one sound per hour, on average, while the stressed plants – both dehydrated and injured – emitted dozens of sounds every hour.”

The recordings collected in this way were analyzed by specially developed machine learning (AI) algorithms. The algorithms learned how to distinguish between different plants and different types of sounds, and were ultimately able to identify the plant and determine the type and level of stress from the recordings. Moreover, the algorithms identified and classified plant sounds even when the plants were placed in a greenhouse with a great deal of background noise.

In the greenhouse, the researchers monitored plants subjected to a process of dehydration over time and found that the quantity of sounds they emitted increased up to a certain peak, and then diminished.

“In this study we resolved a very old scientific controversy: we proved that plants do emit sounds!” says Prof. Hadany. “Our findings suggest that the world around us is full of plant sounds, and that these sounds contain information – for example about water scarcity or injury. We assume that in nature the sounds emitted by plants are detected by creatures nearby, such as bats, rodents, various insects, and possibly also other plants – that can hear the high frequencies and derive relevant information. We believe that humans can also utilize this information, given the right tools – such as sensors that tell growers when plants need watering. Apparently, an idyllic field of flowers can be a rather noisy place. It’s just that we can’t hear the sounds.”

In future studies the researchers will continue to explore a range of intriguing questions, such as: What is the mechanism behind plant sounds? How do moths detect and react to sounds emitted by plants? Do other plants also hear these sounds? Stay tuned.

The research team

“Super Seaweed” Produces Natural Health Compounds and Medicine from the Sea

Written by AUFTAU on 20 March 2023. Posted in Newsroom.

After developing an innovative technology that enables the growth of seaweed enriched with proteins and minerals such as zinc, iron, iodine, magnesium, and calcium for humans and animals, researchers from Tel Aviv University’s School of Zoology at The George S. Wise Faculty of Life Sciences and the Israel Oceanographic and Limnological Research Institute (IOLR) have made a new advancement: They succeeded in significantly increasing the ability of seaweed to produce healthy natural substances, focusing on enhancing the production of bio-active compounds that offer medical benefits to humans, such as antioxidants – the concentration of which was doubled in the seaweed; natural sunscreens – its concentration tripled; and unique protective pigments of great medical value, the concentration of which increased by ten-fold.

The study was carried out with the innovative and sustainable approach of integrated aquaculture, which combines seaweed with fish cultivation, upgrading the seaweed while at the same time helping to purify the seawater and minimizing negative environmental impacts. According to the researchers, these findings may serve the pharmaceutical, cosmetics, food, and nutritional supplement industries.

Manufacturers of Valuable Compounds

The new development was led by Ph.D. student Doron Ashkenazi of Tel Aviv University and the Israel Oceanographic and Limnological Research Institute, under the guidance of Prof. Avigdor Abelson of Tel Aviv University’s School of Zoology and Prof. Alvaro Israel of the IOLR in Haifa, in collaboration with other leading researchers from Israel and around the world, including Guy Paz from IOLR; organic chemistry expert Dr. Shoshana Ben-Valid; Dr. Eitan Salomon from the National Center for Mariculture in Eilat; and Prof. Félix López Figueroa, Julia Vega, Nathalie Korbee, and Marta García-Sánchez from Malaga University in Spain. The article was published in the scientific journal Marine Drugs.

Ph.D. student Doron Ashkenazi (left) and Prof. Avigdor Abelson (right)

Doron Ashkenazi explains that “seaweed, also known as macroalgae, are marine plants that form the basis of the coastal marine ecosystem. The seaweed absorb carbon dioxide and release oxygen into the environment. They purify the water, provide food, habitat, and shelter for numerous species of fish and invertebrates. Not many know that seaweed also produce a wide variety of distinct bio-active compounds that are beneficial to humans. The seaweed living in the intertidal zone face extreme stress conditions, which include changes in salinity, temperature, desiccation [loss of moisture] conditions, changes in the availability of nutrients and high exposure to solar radiation, especially in the ultraviolet (UV) range.”

“Not many know that seaweed also produce a wide variety of distinct bio-active compounds that are beneficial to humans.” Doron Ashkenazi

To survive, the seaweed has developed a unique set of chemical defense mechanisms – natural chemicals that help them cope with these harsh environments. They are highly efficient natural factories that produce valuable substances that may offer significant benefits to humans.

In the current study, they sought to examine whether and how it is possible to increase and maximize the seaweed’ production of bio-active compounds, and secondary metabolites, that offer significant health benefits. These substances include antioxidants, protective pigments, and natural UV radiation filters.

A dedicated aquaculture system where the researchers grew three local species of algae

Future Looking Greener Than Ever?

To this end, the researchers developed an original and practical cultivation approach, whereby three local seaweed – Ulva, Gracilaria and Hypnea – were initially grown alongside fish effluents, and subsequently exposed to stressors including high irradiance, nutrient starvation, and high salt content.

They investigated how these changes affected the concentration of specific valuable biomaterials in the seaweed, to enhance their production. The results were impressive: antioxidant levels had doubled, seaweed natural sunscreen molecules tripled, and protective pigments were increased by ten-fold. “We developed optimal cultivation conditions and invented a new and clean way to increase the levels of healthy natural bio-active compounds in seaweed to an unprecedented level,” says Ashkenazi. “We in fact produced ‘super seaweed’ tailor designed to be utilized by the emerging health industries for food and health applications.”

“In the future, humanity will focus on creating science-based environmental solutions (…) technologies that promote recycling and the sound use of natural resources without overexploiting them.” Doron Ashkenazi

The researchers believe that in the future it will be possible to use their cultivation approach to elevate in seaweed additional natural materials with important medical properties, such as anti-cancer, anti-diabetic, anti-inflammatory, anti-viral, and ant-biotic substances.

They also emphasize that seaweed aquaculture is environmentally friendly, preserving the ecological balance, and reducing environmental risks by minimizing excessive amounts of pollutants caused by humans, reducing the emission of greenhouse gases, and lowering the carbon footprint. In this way, seaweed aquaculture can help cope with global environmental challenges such as pollution, habitat loss, and the climate crisis.

“In the future, humanity will focus on creating science-based environmental solutions, like the one we offer in this study – technologies that promote recycling and the sound use of natural resources without overexploiting them. Our study demonstrates how we can enjoy nature without harming it,” concludes Ashkenazi.

World’s First mRNA Vaccine Against Deadly Bacteria

Written by AUFTAU on 15 March 2023. Posted in Newsroom.

Israeli researchers develop vaccine that is 100% effective against bacteria lethal to humans.

For the first time worldwide, a team of researchers from Tel Aviv University and the Israel Institute for Biological Research have developed an mRNA-based vaccine that is 100% effective against a type of bacteria that is lethal to humans. The study, conducted in a lab model, demonstrated that all treated models were fully protected against the bacteria. The researchers believe their new technology can enable rapid development of effective vaccines for bacterial diseases, including diseases caused by antibiotic-resistant bacteria, for example in case of a new fast-spreading pandemic.

“In our study we proved that it is, in fact, possible to develop mRNA vaccines that are 100% effective against deadly bacteria.” Dr. Edo Kon

Quickly Developed

The study was led by Tel Aviv University’s Dr. Edo Kon and Prof. Dan Peer, VP for R&D and Head of the Laboratory of Precision Nano-Medicine at The Shmunis School of Biomedicine and Cancer Research at The George S. Wise Faculty of Life Sciences, in collaboration with researchers from the Israel Institute for Biological Research: Dr. Yinon Levy, Uri Elia, Dr. Emanuelle Mamroud, and Dr. Ofer Cohen. The results of the study were published in the journal Science Advances.

“So far, mRNA vaccines, such as the COVID-19 vaccines which are familiar to all of us, were assumed to be effective against viruses but not against bacteria,” explains Dr. Edo Kon. “The great advantage of these vaccines, in addition to their effectiveness, is the ability to develop them very quickly: once the genetic sequence of the virus SARS-CoV2 (COVID-19) was published, it took only 63 days to begin the first clinical trial. However, until now scientists believed that mRNA vaccines against bacteria were biologically unattainable. In our study we proved that it is, in fact, possible to develop mRNA vaccines that are 100% effective against deadly bacteria.”

Running RNA gel

Combining Breakthrough Strategies

The researchers explain that viruses depend on external (host) cells for their reproduction. Inserting its own mRNA molecule into a human cell, a virus uses our cells as a factory for producing viral proteins based on its own genetic material, namely replicates of itself.

In mRNA vaccines this same molecule is synthesized in a lab, then wrapped in lipid nanoparticles resembling the membrane of human cells. When the vaccine is injected into our body, the lipids stick to our cells, and consequently the cells produce viral proteins. The immune system, becoming familiar with these proteins, learns how to protect our body in the event of exposure to the real virus.

Since viruses produce their proteins inside our cells, the proteins translated from the viral genetic sequence resemble those translated from the lab-synthesized mRNA.

“If tomorrow we face some kind of bacterial pandemic, our study will provide a pathway for quickly developing safe and effective mRNA vaccines.” Prof. Dan Peer

Bacteria, however, are a whole different story: They don’t need our cells to produce their own proteins. And since the evolutions of humans and bacteria are quite different from one another, proteins produced in bacteria can be different from those produced in human cells, even when based on the same genetic sequence.

“Researchers have tried to synthesize bacterial proteins in human cells, but exposure to these proteins resulted in low antibodies and a general lack of protective immune effect, in our bodies,” explains Dr. Kon. “This is because, even though the proteins produced in the bacteria are essentially identical to those synthesized in the lab, being based on the same ‘manufacturing instructions’, those produced in human cells undergo significant changes, like the addition of sugars, when secreted from the human cell.”

“To address this problem, we developed methods to secrete the bacterial proteins while bypassing the classical secretion pathways, which are problematic for this application. The result was a significant immune response, with the immune system identifying the proteins in the vaccine as immunogenic bacterial proteins. To enhance the bacterial protein’s stability and make sure that it does not disintegrate too quickly inside the body, we buttressed it with a section of human protein. By combining the two breakthrough strategies we obtained a full immune response.”

WATCH: Prof. Dan Peer and Dr. Edo Kon on the world’s first mRNA vaccine for deadly bacteria

Solution to Antibiotic-resistant Bacteria?

“There are many pathogenic bacteria for which we have no vaccines,” adds Prof. Peer. “Moreover, due to excessive use of antibiotics over the last few decades, many bacteria have developed resistance to antibiotics, reducing the effectiveness of these important drugs. Consequently, antibiotic-resistant bacteria already pose a real threat to human health worldwide. Developing a new type of vaccine may provide an answer to this global problem.”

“In our study, we tested our novel mRNA vaccine in animals infected with a deadly bacterium. Within a week, all unvaccinated animals died, while those vaccinated with our vaccine remained alive and well. Moreover, in one of our vaccination methods, one dose provided full protection just two weeks after it was administered. The ability to provide full protection with just one dose is crucial for protection against future outbreaks of fast-spreading bacterial pandemics. It is important to note that the COVID-19 vaccine was developed so quickly because it relied on years of research on mRNA vaccines for similar viruses. If tomorrow we face some kind of bacterial pandemic, our study will provide a pathway for quickly developing safe and effective mRNA vaccines.”

The study was funded by research grants from the European Union (ERC; EXPERT) and the Shmunis Family (for Prof. Peer).

Do We Need ‘Junk DNA’?

Written by AUFTAU on 15 March 2023. Posted in Newsroom.

Researchers offer possible reason why neutral sequences in the genome of living creatures continue to exist millions of years later.

A new model developed at Tel Aviv University offers a possible solution to the scientific question of why neutral sequences, sometimes referred to as “junk DNA”, are not eliminated from the genome of living creatures in nature and continue to exist within it even millions of years later.

According to the researchers, the explanation is that junk DNA is often located in the vicinity of functional DNA. Deletion events around the borders between junk and functional DNA are likely to damage the functional regions and so evolution rejects them. The model contributes to the understanding of the huge variety of genome sizes observed in nature.

Border Induced Selection

The model describes a phenomenon which the team of researchers refer to as “border induced selection,” and was developed under the leadership of PhD student Gil Loewenthal in the laboratory of Prof. Tal Pupko from the Shmunis School of Biomedicine and Cancer Research at the The George S. Wise Faculty of Life Sciences and in collaboration with Prof. Itay Mayrose, also from TAU’s Faculty of Life Sciences. The study was published in the journal Open Biology.

Throughout evolution, the size of the genome in living creatures in nature changes. For example, some salamander species have a genome ten times larger than the human genome. “The rate of deletions and short insertions, dubbed ‘indels’, is usually measured by examining pseudogenes,” explains Prof. Pupko. “Pseudogenes are genes that have lost their function, and in which there are frequent mutations, including deletions and insertions of DNA segments.”

In previous studies that characterized the indels, it was found that the rate of deletions is greater than the rate of additions in a variety of creatures including bacteria, insects, and even mammals such as humans.

Prof. Tal Pupko

Reverse Bias for Short Segments

The question the researchers sought to answer is how the genomes are not deleted when the probability of DNA deletion events is significantly greater than DNA addition events: “We have provided a different view to the dynamics of evolution at the DNA level,” says Loewenthal. “When measuring the rate of indels there will be more deletions, but the measurements are carried out in pseudogenes which are quite long sequences. We assert that in shorter neutral segments, deletions would likely remove adjacent functional segments which are essential for the functioning of the organism, and they will therefore be rejected [through ‘border-induced selection’]. Accordingly, we assert that when the segment is short, there will be a reverse bias – there will be more insertions than deletions – and therefore short neutral segments are usually retained.”

“In our study, we simulated the dynamics of indels, while taking into account the effect of ‘border-induced selection,’ and compared the simulation results to the distribution of human intron lengths (introns are DNA segments in the middle of a protein-coding gene, which themselves do not code for a protein). A good match was obtained between the results of the simulations and the distribution of lengths observed in nature, and we were able to explain peculiar phenomena in the length distribution of introns, such as the large variation in intron lengths, as well as the complex shape of the distribution which does not look like a standard bell curve.”

New Snake Family Identified

Written by AUFTAU on 2 March 2023. Posted in Newsroom.

An extensive international study identified a new family of snakes: Micrelapidae. According to the researchers, Micrelaps, small snakes usually with black and yellow rings, diverged from the rest of the evolutionary tree of snakes about 50 million years ago. As far as they know, the new family includes only three species, one in Israel and neighboring countries, and two in East Africa.

“Today we tend to assume that most large groups of animals, such as families, are already known to science, but sometimes we still encounter surprises, and this is what happened with Micrelapid snakes.” Prof. Shai Meiri

Exploring the Micrelaps’ Family Tree

The study was conducted by Prof. Shai Meiri of TAU’s School of Zoology, The George S. Wise Faculty of Life Sciences, and of The Steinhardt Museum of Natural History Museum, as well as researchers from Finland, the USA, Belgium, Madagascar, Hong Kong, and Israel. The paper was published in Molecular Phylogenetics and Evolution.

“Today we tend to assume that most large groups of animals, such as families, are already known to science, but sometimes we still encounter surprises, and this is what happened with Micrelapid snakes,” explains Prof Meiri.

“For years, they were considered members of the largest snake family, the Colubridae, but multiple DNA tests conducted over the last decade contradicted this classification. Since then, snake researchers around the world have tried to discover which family these snakes belong to – to no avail. In this study we joined the scientific effort.”

The researchers used micro-CT technology – high-resolution magnetic imaging, to examine the snake’s morphology, focusing specifically on the skull. In addition, they applied methods of deep genomic sequencing – examining about 4,500 ultra-conserved elements, namely regions in the genome that take millions of years to exhibit any change.

Prof. Meiri explains that “in addition to the DNA of Micrelaps, we sampled DNA from various snake groups to which they might have belonged. This way, we discovered some unique genomic elements in Micrelaps, which were not found in any of the other groups.”

Prof. Shai Meiri

“Even through these snakes have been known for decades, they were mistakenly included in other families for many years.” Prof. Shai Meiri

Family Relocation

According to the researchers their findings indicate that Micrelaps diverged from the rest of the evolutionary tree of snakes about 50 million years ago. Since then, these snakes have evolved independently, as a distinct and separate family.

Apparently, this is a very small family, including only three species: two in Kenya and Tanzania in East Africa, and one in Israel and nearby regions (northern Jordan and the Palestinian Authority, southern Syria, and southern Lebanon). The geographic dispersion suggests that these snakes probably originated in Africa, and then, at some point in their history, some of them made their way north through the Great Rift Valley.

“In this study we were able to associate a new snake family – the Micrelapidae. Even through these snakes have been known for decades, they were mistakenly included in other families for many years. Since most animals have already been classified into well-defined families, such a discovery of a new family is quite a rare occurrence in modern science,” concludes Prof. Meiri.

Featured image: Small with black and yellow rings, some 50 million years old. Meet the Micrelaps snake (photo: Alex Sablenco )