Scientist identify candidate genes associated with albinism in Wels catfish

Peer-Reviewed Publication

ESTONIAN RESEARCH COUNCIL

 

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ALBINO WELS CATFISH (PHOTO: ANTI VASEMÄGI)

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CREDIT: ANTI VASEMÄGI, RIHO GROSS

An international research team from Estonian University of Life Sciences and Swedish University of Agricultural Sciences has discovered a set of candidate genes causing albinism in one of the largest freshwater fish, Wels catfish (Silurus glanis).

Lack of pigmentation, a condition known as albinism, is a rare event which occurs occasionally across different taxa. It is usually caused by specific changes in the genome. Yet identifying exact molecular culprits for different species is not a simple task. This is because the melanin pigment synthesis and metabolism pathways, which are responsible for most types of pigmentation in animals, are relatively complex. As a result, mutations in many different genes can cause albinism. "Essentially, albinism is a phenomenon where, as a result of a mutation, a gene no longer functions normally or is completely shut down," said Vasemägi, the leading scientist of the study. "The mechanisms of albinism can therefore be compared to an airplane that cannot take off due to unknown malfunction. Complex systems, such as metabolic pathways or airplanes, can become non-functional in many different ways from leaks in the fuel tank to the absence of a pilot. Therefore, the number of potential genes responsible for this loss-of-function trait causing albinism is relatively large, especially when we consider a broader evolutionary context beyond primates," he added.

"During the study, we analysed the expression patterns and splicing variation of more than ten thousand genes in four different tissues, and discovered a plenty of differences between albino and normally pigmented catfish," explained Vasemägi. "We identified several genes across multiple tissues as the most promising candidates, such as hps4, hsp90b1, raph1, uqcrfs1 genes, potentially causally linked to the albino phenotype in Wels catfish. Interestingly, these genes also cause albinism and pigmentation disorders in humans, channel catfish and mice. On the other hand, very few alternatively spliced genes showed consistent association with pigmentation, which indicates that the observed alternative splicing cases are most likely not causally linked with albinism in Wels catfish,” he added.

"During the differential gene expression analysis, we also observed significant differences between albino and pigmented catfish related to general energy metabolism and the immune system, supporting previous physiological studies," added Professor Riho Gross, head of the Chair of Aquaculture at the Estonian University of Life Sciences, who participated in the study. Prof. Gross has been leading an innovation project funded by the European Maritime and Fisheries Fund, the aim of which was to develop and optimize the technology of artificial propagation and breeding of Wels catfish in Estonia and to identify populations with the best fish farming characteristics and genetic indicators.

This work provides the first transcriptome-wide multi-tissue insights into the albinism of Wels catfish and serves as a valuable resource for further understanding the genetic mechanisms of pigmentation in fish.
The results described in this article are published in Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology. The project was funded by Estonian Research Council and the European Maritime and Fisheries Fund.

M.Y. Ozerov, K. Noreikiene, S. Kahar, M. Flajšhans, R. Gross, A. Vasemägi (2024) Differential expression and alternative splicing analyses of multiple tissues reveal albinism-associated genes in the Wels catfish (Silurus glanis). Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 110941. https://doi.org/10.1016/j.cbpb.2024.110941

  

Normally pigmented Wels catfish (photo: Anti Vasemägi)

Albino Wels catfish in fish hatchery (photo: Riho Gross)

JOURNAL

Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology

DOI

10.1016/j.cbpb.2024.110941 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Differential expression and alternative splicing analyses of multiple tissues reveal albinism-associated genes in the Wels catfish (Silurus glanis)

How to elicit an authentic ‘yes’

Peer-Reviewed Publication

CORNELL UNIVERSITY

ITHACA, N.Y. – When making a request of someone, would you like them to answer honestly? Try giving them a script.

That is one recommendation from researchers at the Cornell University School of Industrial and Labor Relations and University of Michigan, who developed strategies to evoke authentic responses from people – even if it’s a hard “no” – instead of acquiescence motivated by awkwardness or guilt.

“Giving People the Words to Say No Leads Them to Feel Freer to Say Yes” published Jan. 5 in Scientific Reports. The co-authors are Rachel Schlund, doctoral student in organizational behavior; Vanessa Bohns, professor and chair in the Department of Organizational Behavior; and Roseanna Sommers, assistant professor of law at Michigan.

“Employees and organizations benefit when people agree to requests freely rather than feeling pressured or coerced, which can lead to resentment and backlash,” Schlund said. “However, requests are inherently difficult to refuse.”

Previous work from the researchers focused on peoples’ reactions to requests and included tactics they can use to feel more comfortable with refusing. Still, those interventions placed the burden of saying “no” on the request’s “target” (i.e., the person being asked), Schlund said.

For their new paper, Schlund, Bohns and Sommers decided to shift that burden.

“We tested an intervention that requesters can use to solicit consent in ways that are experienced as less coercive, shifting some of the burden of saying ‘no’ off the target,” she said.

Giving targets a specific way to decline is particularly effective, the researchers said. The studies included scripts such as: “Before we begin the study, can you please unlock your phone and hand it to me? I’ll just need to take your phone outside of the room for a moment to check for some things. If you’d like to refuse, please say the words, ‘I’d rather not.’ Refusing will not affect your payment or participation in the study.”

In the studies, a small basket was held out for participants to hand over their phones, if they chose to do so.

“We hypothesized that one reason it is so hard for targets to say ‘no’ is that it is difficult to find the words to do so in the moment,” Schlund said. “For this reason, we tested an intervention in which requesters provided targets with an explicit script to refuse as part of their ask. This intervention – telling targets how to say ‘no’ – was more effective at increasing targets’ feelings of freedom to say ‘no’ to an invasive request than simply telling targets they could say ‘no.’” 

For additional information, see this Cornell Chronicle story.

Cornell University has dedicated television and audio studios available for media interviews.

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-023-50532-3 

 

COVID-19 pandemic perceived as less serious than other health problems

Peer-Reviewed Publication

UNIVERSITY OF GOTHENBURG

A large seven-country study has shed light on how serious people find the COVID-19 pandemic compared to other major public health problems. The results were surprising and provide guidance to healthcare providers as well as policymakers.

Researchers from seven Environment for Development (EfD) centers plus the EfD Global Hub, located at the University of Gothenburg, have conducted an extensive survey on how serious people perceive COVID-19. This study is now bearing fruit in the form of publications, the first being: Perceptions of the seriousness of major public health problems during the COVID-19 pandemic in seven middle-income countries.

Respiratory illnesses ranked more serious
Over 10,000 respondents ranked the seriousness of the seven health problems (alcoholism and drug use, HIV/AIDS, malaria, tuberculosis, lung cancer and respiratory diseases caused by air pollution and smoking, and water-borne diseases like diarrhea).

Their answers revealed that in most countries respiratory illnesses were perceived to be a more serious problem than COVID-19. Surprisingly, in six of the seven countries, respondents ranked waterborne diseases as the least serious health problem. In the seventh country (South Africa) it was ranked next to last. In Africa, people felt that alcoholism and drug use were also more serious than COVID-19.

Don’t crowd out ordinary healthcare
These findings are important because they show that people still care about the health problems they were facing before the pandemic.

“An important lesson for health ministries is to not get too carried away by what media focuses on a particular point in time. It is important to avoid crowding out ordinary health services,” says Dale Whittington.

“It’s also clear that public perceptions of the seriousness of health problems can differ considerably within and across countries and population segments defined by demographics and knowledge.”

EfD Director Gunnar Köhlin notes that the study is unique in the way it has tied together researchers from seven countries in the Global South with leading researchers in the US and Sweden in a joint data collection and analysis effort.

“A study like this can put novel phenomena, such as the COVID-19 pandemic, into a perspective of the more persistent challenges the countries in the Global South face,” he says.

About the study:
Countries included in the study: Colombia, South Africa, India, Kenya, Nigeria, Tanzania, and Vietnam.

The study was led by professors Richard Carson, Dale Whittington, and Michael Hanemann. The researchers designed a survey and used the research company YouGov’s internetpanel to send it to over 10,000 recipients in seven countries, in early 2022.

Contact:
For more information, contact: Gunnar Köhlin, Director EfD, gunnar.kohlin@efd.gu.se, +46 31 786 4426.

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JOURNAL

Communications Medicine

DOI

10.1038/s43856-023-00377-8 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Perceptions of the seriousness of major public health problems during the COVID-19 pandemic in seven middle-income countries

 

Sustainable practices can save Mexico's blue agave, tequila and bats

Peer-Reviewed Publication

UNIVERSITY OF GOTHENBURG

Many associate tequila with lime wedges, salt, and parties. But the popular drink also has a negative impact on biodiversity, both on the blue agave from which it is made and, perhaps more unexpectedly, on bats. Both are threatened by one-sided cultivation. Researchers at the University of Gothenburg, together with colleagues in Mexico and the USA, have studied which measures can have a positive effect on biological diversity.

The increasing global popularity of tequila has driven increasingly intensive cultivation of blue agave. Most producers work with an asexual reproduction technique that prevents the plants from flowering. When flowering, the sugar goes to the nectar in the flowers and the plant is no longer useful for tequila production. This technique damages the agave's genetic diversity and puts the crop at long-term risk. It becomes less resistant to, for example, pests and climate change. In addition, intensive cultivation methods have removed an important source of nutrition from bats that pollinate the flowers and feed on the nectar from the agave.

Voluntary programs, such as the "bat-friendly program," allow tequila producers to label their bottles with a hologram if they allow sexual reproduction. Then the price will be slightly higher, which can be justified with the environmental label. However, since many farmers only grow agave for sale to distilleries and do not produce tequila themselves, these hologram initiatives are not enough, farmers must also have incentives for sustainable cultivation.

In a new study, a survey method was used to find out what it takes for agave farmers to want to use methods that allow some natural agave flowering and seed production.

On average, farmers said they could consider allowing 93 plants (out of about 3,000) per hectare to flower for unspecified future yield increases, 129 plants for a subsidy of 20% relative to the investment cost, and 180 plants if the subsidy was 50% of the investment cost. According to the bat-friendly program, 150 plants per hectare are enough to secure biodiversity and food for the bats.

With sufficient financial incentives and educational resources, many farmers seem willing to invest a portion of their harvests to benefit bats while increasing agave genetic biodiversity and future viability. The researchers also note that collaboration between industry, consumers, decision-makers, and nature conservation groups is required. The research findings suggest that environmental benefits and appropriate financial incentives could make "bat-friendly" tequila a sustainable option at the party.

About the study
The study is carried out by Alejandro Lopez-Feldman, Environment for Development, School of Business, Economics and Law at the University of Gothenburg, Irene Zapata-Moran, University of Wyoming, and Hernan Bejarano, Cide University, Mexico City.
Read the full report!

Contact
For more information, contact: Alejandro Lopez-Feldman, Environment for Development, School of Business, Economics and Law at the University of Gothenburg alejandro.lopez.feldman@efd.gu.se, +46-766-229248.

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JOURNAL

Environmental Research Communications

DOI

10.1088/2515-7620/ad19f4 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Tequila, bats, and agave farmers: towards an understanding of the right incentives to protect genetic diversity

 

Decoding how the brain manages the appetite for salt and water

Peer-Reviewed Publication

TOKYO INSTITUTE OF TECHNOLOGY

 

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THIS STUDY REVEALS KEY ASPECTS OF THE FEEDBACK MECHANISMS REGULATING THE THIRST AND SALT APPETITE.

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CREDIT: TOKYO TECH

Staying hydrated and consuming appropriate amounts of salt is essential for the survival of terrestrial animals, including humans. The human brain has several regions constituting neural circuits that regulate thirst and salt appetite, in intriguing ways.

Previous studies suggested that water or salt ingestion quickly suppresses thirst and salt appetite before the digestive system absorbs the ingested substances, indicating the presence of sensing and feedback mechanisms in digestive organs that help real-time thirst and salt appetite modulation in response to drinking and feeding. Unfortunately, despite extensive research on this subject, the details of these underlying mechanisms remained elusive.

To shed light on this matter, a research team from Japan has recently conducted an in-depth study on the parabrachial nucleus (PBN), the brain’s relay center for ingestion signals coming from digestive organs. Their latest paper, whose first author is Assistant Professor Takashi Matsuda from Tokyo Institute of Technology, was published in Cell Reports on January 23, 2024.

The researchers conducted a series of in vivo experiments using genetically engineered mice. They introduced optogenetic (and chemogenetic) modifications and in vivo calcium imaging techniques into these mice, enabling them to visualize and control the activation or inhibition of specific neurons in the lateral PBN (LPBN) using light (and chemicals). During the experiments, the researchers offered the mice—either in regular or water- or salt-depleted conditions—water and/or salt water, and monitored neural activities along with the corresponding drinking behaviors.

In this way, the team identified two distinct subpopulations of cholecystokinin mRNA-positive neurons in the LPBN, which underwent activation during water and salt intake. The neuronal population that responds to water intake projects from the LPBN to the median preoptic nucleus (MnPO), whereas the one that responds to salt intake projects to the ventral bed nucleus of the stria terminalis (vBNST). Interestingly, if the researchers artificially activated these neuronal populations through optogenetic (genetic control using light) experiments, the mice drank substantially less water and ingested less salt, even if they were previously water- or salt-deprived. Similarly, when the researchers chemically inhibited these neurons, the mice consumed more water and salt than usual.

Therefore, these neuronal populations in the LPBN are involved in feedback mechanisms that reduce thirst and salt appetite upon water or salt ingestion, possibly helping prevent excessive water or salt intake. These results, alongside their previous neurological studies, also reveal that MnPO and vBNST are the control centers for thirst and salt appetite, integrating promotion and suppression signals from several other brain regions. “Understanding brain mechanisms controlling water and salt intake behaviors is not only a significant discovery in the fields of neuroscience and physiology, but also contributes valuable insights to understand the mechanisms underlying diseases induced by excessive water and salt intake, such as water intoxication, polydipsia, and salt-sensitive hypertension,” remarks Dr. Matsuda.

Prof. Noda mentions, “Many neural mechanisms governing fluid homeostasis remain undiscovered. We still need to unravel how the signals for inducing and suppressing water and salt intake, accumulated in the MnPO and vBNST, are integrated and function to control intake behaviors.”

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JOURNAL

Cell Reports

DOI

10.1016/j.celrep.2023.113619 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Two parabrachial Cck neurons involved in the feedback control of thirst or salt appetite

ARTICLE PUBLICATION DATE

23-Jan-2024

 

Dragonfly wings used to study relationship between corrugated wing structure and vortex motions

Corrugated wings exhibit larger lift than flat wings

Peer-Reviewed Publication

HIROSHIMA UNIVERSITY

 

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AFTER A SUDDEN START, THE WING'S AIRFLOW COMES INTO PLAY. THE RED AND BLUE AREAS SHOW POSITIVE AND NEGATIVE VORTICITY, REPRESENTING COUNTERCLOCKWISE AND CLOCKWISE FLOWS. THE CURVES DEPICT STREAMLINES. A CORRUGATED STRUCTURE NEAR THE FRONT EDGE DISRUPTS A CRUCIAL RED FORMATION, A KEY PLAYER IN LIFT ENHANCEMENT.

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CREDIT: YUSUKE FUJITA, HIROSHIMA UNIVERSITY

Scientists from Hiroshima University undertook a study of dragonfly wings in order to better understand the relationship between a corrugated wing structure and vortex motions. They discovered that corrugated wings exhibit larger lift than flat wings.

Their work was published in the journal Physical Review Fluids on December 7, 2023.

The researchers set out to determine if the corrugation of a dragonfly's wing is a secret ingredient for boosting lift. While past research has largely zoomed in on the steady flow around the wing during forward motion, the impact of vortices spawned by its corrugated structure on lift has remained a mystery. 

The wing surfaces of insects like dragonflies, cicadas, and bees, are not flat like the wings on a passenger plane. The insect wings are composed of nerves and membranes, and their cross-section shapes consist of vertices (nerves) and line segments (membranes). The geometry of the shape appears as a connection of objects with a V-shape or other shapes.

Earlier studies have shown that corrugated wings, with their ridges and grooves, have a better aerodynamic performance than smooth wings at low Reynolds numbers. In aerodynamics, the Reynolds number is a quantity that helps predict the flow pattern of fluids. The earlier aerodynamic studies on corrugated wings have contributed to applications in small flying robots, drones, and windmills. Because insects possess low muscular strength, in some way their corrugated wings must give them aerodynamic advantages. Yet scientists have not fully understood the mechanism at work because of the complex wing structure and flow characteristics.

The researchers used direct numerical calculations to analyze the flow around a two-dimensional corrugated wing and compared the corrugated wing performance to that of a flat wing. They focused their study on the period between the initial generation of the leading-edge vortex and subsequent interactions before detachment. They discovered that the corrugated wing performance was better when the angle of attack, that angle at which the wind meets the wing, was greater than 30°.

The corrugated wing’s uneven structure generates an unsteady lift because of complex flow structures and vortex motions. “We've discovered a boosting lift mechanism powered by a unique airflow dance set off by a distinct corrugated structure. It can be a game-changer from the simple plate wing scenario!” said Yusuke Fujita, a PhD student at the Graduate School of Integrated Sciences for Life, Hiroshima University.

The researchers constructed a two-dimensional model of a corrugated wing using a real-life dragonfly wing. The model consisted of deeper corrugated structures on the leading-edge side and less deep, or flatter, structures on the trailing-edge side. Using their two-dimensional model, they further simplified the wing motion and focused on unsteady lift generation by translating from rest. Translational motion, or sliding motion, is a principal component of wing motion, in addition to pitching and rotation. The researchers’ analysis expands the understanding of the nonstationary mechanisms that dragonflies use during flight.

The research team considered two-dimensional models in their study. However, their work focused on the aerodynamics of insect flight, where the flow is typically three-dimensional. “If these results are expanded to a three-dimensional system, we expect to gain more practical knowledge for understanding insect flight and its application in the industry,” said Makoto Iima, a professor at the Graduate School of Integrated Sciences for Life, Hiroshima University.

Looking ahead, the researchers will focus their investigations on three-dimensional models. “We kicked things off with a two-dimensional corrugated wing model in a sudden burst of motion. Now, we embark on the quest to explore the lift-boosting across a broader range of wing shapes and motions. Our ultimate goal is crafting a new bio-inspired wing with high performance by our lift-enhancing mechanism,” said Fujita.

The research team includes Yusuke Fujita, a PhD student, and Makoto Iima, a professor, both from the Graduate School of Integrated Sciences for Life, Hiroshima University. Their research is funded by the Japan Society for the Promotion of Science KAKENHI and the SECOM Science and Research Foundation.

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About Hiroshima University

Since its foundation in 1949, Hiroshima University has striven to become one of the most prominent and comprehensive universities in Japan for the promotion and development of scholarship and education. Consisting of 12 schools for undergraduate level and 4 graduate schools, ranging from natural sciences to humanities and social sciences, the university has grown into one of the most distinguished comprehensive research universities in Japan. English website: https://www.hiroshima-u.ac.jp/en

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JOURNAL

Physical Review Fluids

DOI

10.1103/PhysRevFluids.8.123101 

ARTICLE TITLE

Dynamic lift enhancement mechanism of dragonfly wing model by vortex-corrugation interaction

 

Peach-palm waste and Trichoderma stromaticum: The potential of Cost-effective amylase production

Peer-Reviewed Publication

TSINGHUA UNIVERSITY PRESS

 

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RESPONSE SURFACE FOR MIXTURE DESIGN OF EXPERIMENT THAT OPTIMIZES THE PROPORTIONS BETWEEN COCOA BEAN PEEL, PEPTONE, AND AMMONIUM PHOSPHATE ADDED TO THE PEACH PALM WASTE UNDER SOLID STATE FERMENTATION BY TRICHODERMA STROMATICUM AM7 (CCMB617P) AT 30 °C FOR 6 DAYS, FOR AMYLASE SYNTHESIS (USING THE SPECIAL CUBIC MODEL). THE COPYRIGHT IS RETAINED BY THE AUTHORS.

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CREDIT: DR. ANDRÉA MIURA DA COSTA, DEPARTMENT OF BIOLOGICAL SCIENCES, UNIVERSIDADE ESTADUAL DE SANTA CRUZ, ILHÉUS, BAHIA, BRAZIL

Amylases are among the most important biotechnological and industrial enzymes that can be applied in various sectors, such as food, pharmaceuticals, textiles, chemicals, paper, and detergents.

 

The enzymes’ costs come from a range of factors including the quantity produced, the production process, the expense of its recovery, and the degree of purity at which it will be marketed, etc. The use of agro-industrial substrates and microorganisms brings the potential to low-cost enzyme production. Meanwhile, due to the ability to improve physical and chemical resistance to industrial environmental extremes, such as high temperature and pH, as well as carry out different catalytic reactions, microbial enzymes are favorite to meet the demands of the industry.

 

This innovative study led by Dr. Andréa Miura da Costa (Universidade Estadual de Santa Cruz) reported the amylase production by Trichoderma stromaticum AM7 using peach-palm waste as substrate.

 

A mixture simplex centroid design of the experiment was performed and the surface response methodology was applied to determine the mathematical model that describes the relation between the response variable and the independent factors (nitrogen source proportions). The team found that the design of the optimum proportion for the final mixture was 70% peptone, 24.3% ammonium phosphate, and 5.7% cocoa bean peel. After the addition of nitrogen sources as peptone and ammonium phosphate, the amylase production increased by 45% by T. stromaticum AM7.

 

The researchers also determined the pH and temperature optimum for amylase stability, as well as the effects of metal ions and chemical reagents on amylase activity. They found that the biochemical properties of the amylase showed its stability to acidic pH (4.0) and high temperatures up to 50–60 °C; In addition, the enzyme was little influenced by the presence of ions and denaturing agents, which gives the characteristic of the T. stromaticum AM7 amylase promising for applications mainly in the food sector.

 

In this innovative research, the fungus T. stromaticum AM7 was efficient in producing amylase using peach palm waste as low-cost substrate in solid state fermentation which simplifies and makes fermentation economically viable for this enzyme production. “The cost-effective enzyme extraction and stable amylase highlight its strong potential in industry applications, especially in food processes”, Dr. Andréa Miura da Costa said.

 

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See the article:

Utilization of Peach-palm waste for cost-effective amylase production by Trichoderma stromaticum: Stability and industrial potential

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About Mycology

Mycology —— An International Journal on Fungal Biology is a renowned international, peer-reviewed, open access journal that publishes all aspects of mycological research, sponsored by the Institute of Microbiology, Chinese Academy of Sciences and the Mycological Society of China. Since its inception in 2010, Mycology received strong support from mycologists around the world. By publishing cutting-edge research and facilitating collaborations, Mycology strives to advance the understanding and knowledge of mycology, while fostering innovative research and scientific discussions in the field.

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JOURNAL

Mycology&#58 An International Journal on Fungal Biology

DOI

10.1080/21501203.2023.2276728 

ARTICLE TITLE

Utilization of Peach-palm waste for cost-effective amylase production by Trichoderma stromaticum: Stability and industrial potential

 

Use it or lose it: How seagrasses conquered the sea

Gene analyses revealing the capacity of marine flowering plants to exist under changing environmental conditions provide clues for the conservation and sustainable use of important ecosystems

Peer-Reviewed Publication

HELMHOLTZ CENTRE FOR OCEAN RESEARCH KIEL (GEOMAR)

An international group of 38 researchers coordinated by Professor Dr. Yves Van de Peer, Ghent University, Belgium, Professor Dr. Jeanine Olsen, University of Groningen, Netherlands, Professor Dr. Thorsten Reusch, GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, Dr. Gabriele Procaccini, Stazione Zoologica Anton Dohrn of Napoli, Italy, and the Joint Genome Institute, Berkeley, California, United States of America, sequenced and analyzed the genomes of three of the most important seagrass species – the iconic Mediterranean endemic Neptune grass (Posidonia oceanica), the broadly distributed Little Neptune grass (Cymodocea nodosa) and the Caribbean endemic Turtlegrass (Thalassia testudinum). The researchers first examined genome structure and then compared gene families and pathways associated with structural and physiological adaptations, between the seagrasses and their related freshwater relatives. Their findings are presented today in a peer-reviewed publication in the scientific journal Nature Plants, entitled “Seagrass genomes reveal ancient polyploidy and adaptations to the marine environment”.

Seagrass-based ecosystems provide multiple functions and services – for instance as protection against erosion that preserves coastal seascapes, as biodiversity hotspots for associated animals and algae and as a nature-based solution for climate mitigation owing to their carbon storage capacity in belowground biomass. Both conservation and restoration are areas of intensive research because seagrasses are being lost, as are coral reefs, to climate warming and other human impacts.

As the saying goes, “Many hands/brains make the work light”: To begin, the research consortium took a deep evolutionary look at the structure of the genomes themselves, followed by a comparative analysis of their more than 20,000 genes and relevant pathways that have evolved into the specific marine adaptations. Next, the 23 collaborating research teams each focused on different complementary structural or functional gene sets including their physiological functions. A key question was whether genomic adaptations came about in parallel, or whether they arose independently and maybe even involved different gene sets.

Professor Dr. Olsen points out: “Seagrasses underwent an extremely rare set of adaptations. Whereas re-adaptation to freshwater environments has occurred more than 200 times in flowering plant evolutionary history – involving hundreds of lineages and thousands of species – seagrasses evolved from their freshwater ancestors only three times – involving 84 species. To do this required specialized ecological tolerance to, for example, high salinity, lower light, a wide range of temperature tolerances, underwater carbon capture for photosynthesis, different pathogen defense, structural flexibility and an underwater pollination.”

One major result was that seagrasses were able to jump-start radical adaptation via genome duplication, which is often associated with severe environmental stress.

“Comparison of the three independent seagrass lineages, including freshwater sister lineages, revealed a shared ancient whole genome triplication at about 86 million years. This was quite exciting because large parts of the ocean were oxygen-free at that time and it’s also a uniting event involving the three lineages,” says Professor Dr. Van De Peer.

Further, the researchers found that the retention and expansions of some gene families could still be traced back through retained syntenic blocks to these early duplication events, for example flavonoids to provide protection against ultraviolet radiation and fungi, while stimulating recruitment of nitrogen-fixing bacteria; expanded cysteine oxidases for coping with hypoxic sediments and genes associated with circadian clocks. The results also showed that “jumping genes” – transposable elements – played a major role in creating new genetic variation for selection to act upon. This applied particularly to the large genomes of Thalassia testudinum and Posidonia oceanica.

The team also found several adaptations to be the result of convergence. This applied mainly to traits that became redundant or detrimental in a submerged, highly saline, marine environment. Loss of genes for stomata – the tiny holes in the leaf surface providing gas exchange with the atmosphere – loss of genes for volatiles and signaling to defend against pathogens and tolerate marine heat waves, notably heat shock factors, are compelling examples of “use it or lose it”.

Dr. Procaccini explains: “It’s clear that fine-tuning of supportive pathways has played the dominant role, rather than genes taking on major new functions. Salt-tolerance is a good example in which a higher efficiency of multiple processes has occurred to regulate sodium, chlorine and potassium. Evolutionary changes have also provided different species with the ability to withstand different environments.”

Professor Dr. Reusch summarizes: “Most ecologically important functions are complex traits, involving the interaction of many genes through flexible pathways. With genomic tools now developed for key seagrasses, we can begin to experimentally test and manipulate them. This is especially important for restoration under climate change scenarios involving many of the conditions discussed here.”

The new genomic resources will accelerate experimental and functional studies that are especially relevant to transformative management and restoration of seagrass ecosystems. They are a formidable resource for the research community.

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JOURNAL

Nature Plants

DOI

10.1038/s41477-023-01608-5 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Seagrass genomes reveal ancient polyploidy and adaptation to the marine environment

ARTICLE PUBLICATION DATE

26-Jan-2024

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