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Inside the eggs there is encoded information that the mother wants to pass on to her offspring, which may relate, for example, to her past illnesses. This mechanism – called non-genetic inheritance – is known to scientists, but not yet fully understood. Dr. Taina Rocha de Almeida from the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn explores it.

Dr. Taina Rocha de Almeida is a grantee of the PASIFIC – Marie Skłodowska-Curie COFUND programme. This is a scholarship competition managed by the Polish Academy of Sciences and co-funded by the H2020 Programme „Marie Skłodowska-Curie Actions Co-funding of regional, national and international programmes” and the Polish Ministry of Education and Science.

Her research work focuses on determining to what extent non-genetic inheritance factors affect the adaptability of offspring (from embryo to juvenile stages) to breeding conditions. The researcher’s scientific supervisor is dr. Daniel Żarski from the Department of Gamete and Embryo Biology, IAR&FR PAS.

– This knowledge can be useful for improving fish farming, but also for gaining a deeper understanding of fish immunity, emphasises dr. Taina Rocha de Almeida.

The aim of her ongoing research is to investigate how the eggs transcriptome is linked to progeny performance – by examining embryos and juveniles of two varieties of rainbow trout bred in Poland.

Rainbow trout is one of the most popular farmed species in the world; the second most produced in Europe. As dr. Taina Rocha de Almeida points out, despite advances in knowledge, production is still not as efficient as it could be. – There are many issues hindering the growth of rainbow trout production, but in this research I have focused specifically on two: the productivity of the offspring and resistance to enteric redmouth disease (ERM) or yersiniosis, caused by the bacterium Yersinia ruckeri, which is one of the most serious diseases of salmonids, mainly affecting rainbow trout – she explains.

The transcriptome is a set of RNA molecules in cells that changes according to different factors, e.g. disease. To study the eggs transcriptome (i.e. the information encoded there – in this case for the mRNA-based disease yersiniosis) and its link to offspring performance, the scientist carried out the whole process – from incubation, through the hatching period and the growth of the fish. The fish were then divided into two groups – one was the control group and the other was infected with the aforementioned Yersinia ruckeri bacterium.

The disease causes changes in organs such as the liver, spleen and gills, among others. The scientists therefore took samples of these organs from the infected fish to study the expression of the genes responsible for the immune response there.

In a molecular study of the eggs, the scientist selected 10 genes that play a key role in the immune response of the immune system. She will now compare these with genes from the collected tissues. Dr. Taina Rocha de Almeida also plans to analyse microRNA molecules, the proteome (i.e. the set of proteins present in the cell at any given time) and to study a third variety of rainbow trout, which has also already undergone the entire research process.

The results will show to what extent the information in the eggs influences the performance of the offspring, should they contract a disease popular among rainbow trout. The new knowledge will not only contribute to the advancement of science on the topic of rainbow trout reproduction, but may also find real applications in breeding in the future.

The research was conducted in cooperation with the Dąbie Fish Hatchery and the Faculty of Veterinary Medicine of the University of Warmia and Mazury in Olsztyn.

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The results of the grantee’s research to date were presented at the Leadership Seminar held on 2 February this year.

More about her research can be found here. More about the PASIFIC programme can be found on the PAS website.

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The biological clock helps regulate the timing of various processes in the body. Diurnal variation is shown, among others, by genes regulating insulin sensitivity. Researchers at the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn have shown that the expression of biological clock genes in subcutaneous adipose tissue is linked to insulin action, and is lower in obese people than in those of normal body weight.

Two genes in particular are involved in insulin action: NR1D2 and DBP. – The higher the expression of these genes in adipose tissue, the higher the body’s sensitivity to insulin. And the higher the body’s sensitivity to insulin, the better the regulation of blood glucose levels – explains Professor Marek Strączkowski, head of the Department of Prophylaxis of Metabolic Diseases at the Institute of Animal Reproduction and Food Research (IAR&FR) of the Polish Academy of Sciences in Olsztyn.

The findings of the team led by him were published in the journal Nutrition.

INSULIN AND CIRCADIAN RHYTHM

Insulin is a hormone that increases the transport of glucose into cells, which in turn lowers blood glucose levels. Insulin resistance is a reduced sensitivity of tissues to the action of insulin.

– Insulin resistance in itself is not a disease, but it is a condition that can lead to the development of many diseases: first and foremost type 2 diabetes, but also cardiovascular disease, certain cancers or neurodegenerative diseases – recalls the scientist who is researching the pathogenesis of insulin resistance in people at risk of type 2 diabetes.

The biological clock, on the other hand, is a circadian complex of biochemical processes occurring in the body. The circadian rhythm is controlled centrally and by peripheral clocks in tissues such as subcutaneous adipose tissue. It is an oscillator that stimulates the expression of successive genes encoding proteins responsible for specific biological processes, depending on the time of day or night. Also among the genes regulating insulin sensitivity are those showing diurnal variation, so that the insulin sensitivity of adipose tissue is highest around midday and lowest around midnight.

IMPROVED RESULTS FOLLOWING WEIGHT REDUCTION

Researchers from the IAR&FR PAS decided to combine these issues. To do so, they analysed the expression of subcutaneous adipose tissue clock genes in relation to obesity and insulin sensitivity.

The study group consisted of 38 overweight or obese people. They were examined before and after a 12-week programme of weight reduction through diet. The control group consisted of 16 normal-weight subjects examined only at baseline. Tissue insulin sensitivity was tested using the so-called metabolic clamp method, which is nowadays considered the best method for assessing insulin action in the body.

– Initially, obese subjects had lower expression of biological clock genes in subcutaneous adipose tissue than controls. After weight reduction in the subjects, this expression increased – the researcher reports.

Two genes related to insulin sensitivity in particular are involved: NR1D2 and DBP.

– We have shown that the aforementioned subcutaneous adipose tissue clock genes can be a starting point for further studies to better understand the pathogenesis of insulin resistance. We will explore the problem in further studies, already in cell cultures. This is a developmental topic – concludes Professor Marek Strączkowski.

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On the topic of insulin resistance, a previous publication by researchers from the Department of Prophylaxis of Metabolic Diseases at the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, we wrote here.

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One in ten turkeys may be affected by yellow semen syndrome that causes reduced fertilising ability. The molecular mechanisms of how this condition arises are not yet understood. The key might be a certain protein. Researchers at the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn are investigating it as part of a project funded by the National Science Centre.

The protein in question is a soluble cysteine-rich scavenger receptor protein found in the semen of turkey.
– In mammals, this protein is a very interesting player in the immune system, among other things, it plays an important role in the recognition of microorganisms. Our hypothesis is that the scavenger receptor present in turkey semen is involved in the protection of semen against bacteria – emphasises the project leader Dr. Mariola Słowińska from the Department of Gamete and Embryo Biology of the IAR&FR PAS.

The researchers are also investigating whether this protein could be linked to the mechanism of yellow semen syndrome. – If the results are positive, knowledge of this could be used by breeders in the future to increase the efficiency of chick production by increasing the fertilisation efficiency of turkeys – the researcher adds.

LEARNING ABOUT A NEW PLAYER…

Little is known about the occurrence and role of the protein in focus (soluble cysteine-rich scavenger receptor) in birds.

– A few years ago, our research group was the first in the world to identify this protein in turkey semen. So far, all we know is that it is very similar to proteins of the scavenger receptor family found in mammals, which have the ability to bind to microorganisms and remove microorganisms or their own cells that have been damaged. They are found on the surface of cells of the immune system, e.g. on the surface of macrophages, which, after recognising bacteria or other microorganisms, absorb them (the process of phagocytosis) – explains the scientist, who studies bird reproduction, particularly in turkeys.

Based on this knowledge, scientists want to now study the aforementioned functions in birds. – First of all, we want to know the structure and biological functions of this protein. We have already succeeded in isolating the protein, i.e. obtaining its pure form. We will use this to analyse the physico-chemical properties and modifications of the protein. On this basis, we will create the first structural model of this protein for birds – explains Mariola Słowińska.

The next step will be to produce specific antibodies against the protein, which will allow the researchers, among other things, to localise the protein under study on cells of the immune system, sperm and in organs of the reproductive system. The researchers will examine whether the protein can be a potential marker, i.e. a factor confirming the presence of a particular disease, in this case, yellow semen syndrome. They also plan to learn more about the microbiome of turkey semen to see if the substrate for the development of yellow semen syndrome is a bacterial condition.

As the researcher points out, the project focuses, therefore, not only on learning more about the protein itself, but also provides a broader view on the reproductive and immune systems in birds.

… IN ORDER TO RAPIDLY DIAGNOSE THE DISEASE

Yellow semen syndrome in turkeys leads to disorders in the fertilising capacity of the semen. – Yellow semen contains more abnormal and immature spermatozoa and, in addition, their motility is impaired. On top of this, there is an increased activity of antioxidant enzymes, which indicates imbalance in the oxidative stress (the process in which free radicals attack body cells and cause damage to them) – explains Mariola Słowińska.

The only symptom of yellow semen syndrome in turkeys that is visible at a first glance is the slightly yellowish colour of the semen. However, as the scientist explains, in poultry production semen is collected from many males simultaneously, mixed, and only then is the artificial insemination (an assisted reproduction technique) carried out. – If there is some yellow semen in this pool, the sample will have a reduced fertilisation efficiency – clarifies Mariola Słowińska.

According to the scientific literature, approximately 10 percent of turkeys are affected by yellow semen syndrome.

– With our basic research, we want to deepen our knowledge of the immunology of bird semen, especially in the context of understanding the structure of the soluble cysteine-rich scavenger receptor and its role in the mechanism of yellow semen syndrome. We would also like to detect potential markers of this condition, which would allow rapid diagnosis of sick birds – concludes Mariola Słowińska.

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The project entitled “Soluble scavenger receptor cysteine-rich domain-containing protein – SSc5D, a new player of innate immunity in turkey (Meleagris gallopavo) semen involved in yellow semen syndrome” is financed by the National Science Centre (NCN). The research is being conducted within a consortium formed by the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn and the University of Agriculture in Kraków.

The research team includes: the staff of the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn: Dr. Mariola Słowińska (Principal Investigator), Dr. Ewa Drzewiecka, Ewa Liszewska, MSc, Dr. Anna Szóstek-Mioduchowska, Halina Karol, Eng., Prof. Andrzej Ciereszko, and the staff of the University of Agriculture in Kraków: Dr. Laura Pardyak (coordinator on behalf of the URK), Dr. Zbigniew Arent, Dr. Artur Gurgul, Dr. Ewa Ocłoń, Dr. Tomasz Szmatoła, Dr. Igor Jasielczuk.

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Onion peels, carrot leaves, beet pulp – these are examples of vegetable processing side streams that can be successfully reused, not only in the food industry. However, as food or as a food additive, they can be a source of valuable substances that support our bodies, and this in turn has the potential to respond to the needs of consumers, who are increasingly paying attention to the health-promoting effects of the food they choose.

– Some side streams of vegetable processing can be used in the chemical, cosmetic or pharmaceutical industries. They can also become food or food additives – rich in health-promoting ingredients affecting, among other things, our intestinal microbiome, i.e. the bacteria living in our intestines, which, in turn, can have a positive impact on our immune system, explains Dr Joanna Fotschki of the Department of Immunology and Food Microbiology at the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn.

There is a wealth of scientific evidence to suggest that side streams of vegetable processing can be a source of compounds with anti-inflammatory, antioxidant and cytoprotective properties (protecting the body’s healthy cells from damage), and that they have bioactive compounds that can modulate our gut bacteria.

– For example, tomato pomace extract may exhibit anti-inflammatory and cytoprotective effects, and beetroot pomace may exhibit antioxidant properties. Bioactive compounds, called polyphenols, from red onion husk may have antifungal and antimicrobial properties. Pumpkin seed oil, on the other hand, may prevent obesity caused by a high-fat diet by altering parameters important for lipid metabolism, according to the scientist, who is researching the suitability of plant processing side streams as a source of bioactive substances.

REDUCE WASTE

The vegetable industry generates large amounts of side streams that have the potential to be managed and utilised. – According to estimates, approximately 400,000 tonnes of waste is produced annually in fruit and vegetable processing in Poland. These can include, among others, onion plant husks, pomace, peelings from root vegetables, leafy threads and seeds – says Joanna Fotschki.

These products are most often used to produce compost or biogas. One trend in the use of 'waste’ from seasonal vegetables is also to extract natural food colourings from them for use in the production of beverages, confectionery and bakery products, dairy products and ready meals.

Sometimes, however, improper management of this plant biomass results in it being wasted. Indeed, as the scientist explains, the biggest problem of using post-production waste is the proper protection of this material from microbiological contamination, which consequently prevents its reuse. In addition, the costs of processing such by-products play a big role: drying, technological treatment, storage, transport.

– The side products of processing vegetables such as peppers, tomatoes, lettuce, aubergines and cucumbers, if not processed in a sufficiently short period of time, spoil very quickly, so managing them is a challenge for the food industry, often generating high disposal costs, says the researcher.

On the other hand, she adds, if the tested end product shows health-promoting properties for the consumer, then it will be more profitable for companies to use this 'waste’ than to dispose of it.

LACTIC ACID BACTERIA – GO FOR IT!

In her next research, Dr Joanna Fotschki wants to test whether the lactic fermentation process can be applied to the by-products of carrot processing.

Why such an idea? – Poland is one of the leading producers of carrots in Europe, and lactic fermentation is a well-known way of preserving food and giving it additional health-promoting qualities – the researcher answers.

– Even after technological processes (mainly thermal processes during pomace preservation), pomace is still a valuable raw material and contains biologically active compounds in its composition, which may suggest its potential use as a health-promoting food additive, she points out.

Carrot processing pomace contains many valuable compounds, e.g. fibre, proteins, lipids, essential oils, carbohydrates and phytochemicals (polyphenols and carotenoids). Many of these compounds have bioactive properties and are attributed to health-promoting functions, e.g. immune-enhancing, anti-inflammatory and antioxidant effects.

The use of lactic acid bacteria, on the other hand, can be a method of improving the safety, quality, sensory and nutritional value of fermented food, adds Dr Anna Ogrodowczyk, who works with Dr Joanna Fotschki at the Department of Immunology and Food Microbiology of the IAR&FR PAS in Olsztyn.

– The need for deeper research into plant side products – in order to find a common solution to the problem of waste management, the depletion of natural resources and the growing demand for food, including health-promoting food – seems necessary. At the moment, I am focusing on basic research on a laboratory scale, but in the next stages I would like to see this translated and applied in industry – concludes Joanna Fotschki.

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Fanconi anemia is a very rare genetic disease characterized by i.a. high risk of cancer, especially squamous cell carcinoma of the oral cavity. Due to the small number of patients, it is difficult to conduct clinical trials on it. Scientists from an international team propose to use advanced mathematics, or more precisely, the method of multi-level dynamic modeling, i.e. collecting large amounts and various types of genetic and health data from a limited number of patients.

– Multi-level dynamic modeling is an advanced mathematical and computational approach used in various fields of science and engineering, which allows for analyzing and explaining complex patterns – says Prof. Carsten Carlberg from the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn, one of the corresponding authors of the publication on this topic, which has just been published in the journal „Frontiers in Genetics” .

WHAT KIND OF ILLNESS IS THAT

Fanconi anemia (FA) is a very rare disease with a genetic basis (it occurs once in 300,000 people). It is primarily caused by mutations in 22 different genes involved in repairing damaged DNA.

People with Fanconi anemia often have congenital defects and a high risk of cancer, especially squamous cell carcinoma of the oral cavity. Due to gene mutations and a defect in the DNA repair process, traditional cancer treatment methods such as chemotherapy cannot be used for this disease.

A BROAD LOOK AT THE DATA

The problem in better understanding Fanconi anemia is the small number of patients and, as a result, difficulties in conducting clinical trials with their participation. Advanced mathematics comes to the rescue.

As explained by prof. Carsten Carlberg, mechanistic molecular modeling is a computational approach that is well suited to analyzing longitudinal studies of groups of people with a limited number of participants (longitudinal studies are a way of conducting research that allows you to observe the same people repeatedly and over many years). These limitations may have various reasons: logistical, financial, or because the disease being studied, such as Fanconi anemia, is rare.

In contrast, multi-level dynamic modeling is a special case of mechanistic modeling in which a large amount of data is collected for one person and then used to create models of that person’s cells and tissues. These models are sometimes referred to as „digital twins”.

– To create and „train” the model, we use data from healthy and diseased tissue samples from a unique cohort of 750 patients with FA, which was built over 15 years by Prof. Eunike Velleuer. On this basis, we develop the characteristic features of squamous cell carcinoma in patients with Fanconi anemia, which in turn allows us to develop forecasts regarding the probability of developing this cancer – explains Prof. Carsten Carlberg.

– This approach may revolutionize the way of clinical treatment of people with Fanconi anemia – says the leader of the research team, Prof. Eunike Velleuer from the University of Düsseldorf (Germany), who is one of the world’s leading experts in the field of this disease and the first author of the mentioned publication.

The German-Polish team is completed by international collaborators from Mexico and the US, who are experts in mechanistic modelling and/or Fanconi anemia.. The consortium’s ultimate goal is to create „digital twins” of FA patient which can be used to develop personalized treatment routes.

– Using mechanistic modelling and building medical digital twins is by far not restricted to Fanconi anemia, but can be applied for many investigations such as longitudinal effects of vitamin D supplementation – says Prof. Carlberg.

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Prof. Carsten Carlberg is a world-famous biochemist specializing in vitamin D research. He is the leader of the scientific group dealing with nutrigenomics at the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn.

More about the team’s activities at: https://welcome2.pan.olsztyn.pl/.

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The gut microbiota plays a fundamental role in shaping our health. When its structure and function are disrupted, health problems can arise. Prebiotics and probiotics are helpful in restoring its balance. Researchers from the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn are investigating how supplementation with a prebiotic derived from chicory improves the health of patients with psoriasis.

– We hypothesise that rebalancing the gut microbiota and proper functioning of the intestinal barrier in people with psoriasis will alleviate the symptoms of inflammation and the severity of skin lesions seen in this chronic dermatitis – explains Dr Urszula Krupa-Kozak.

RESTORE THE BALANCE

The intestinal microbiota is a rich and diverse assemblage of microorganisms residing in the gastrointestinal tract that enable the digestion of food, support the proper functioning of the immune system and protect against invasion by pathogenic organisms.

– It is a complex ecosystem residing in our body, without which we are unable to stay healthy. Its close interaction with the intestinal epithelium enables the formation of immune mechanisms. The gut microbiota plays an important role in maintaining the integrity of the intestinal epithelium – that is, the selective barrier that, on the one hand, separates the immune cells located in the intestinal mucosa from the microorganisms present in the intestinal lumen and, at the same time, enables metabolites of the microbiota to interact with host cells, thereby regulating the immune response – explains a scientist from the Department Chemistry and Biodynamics of Food.

An imbalance of the intestinal microbiota (dysbiosis) can therefore result in an increase in the permeability of the intestinal barrier and consequently be the cause of the development of inflammation.

Plaque psoriasis is a chronic immune-mediated dermatitis. It is a non-communicable disease, affecting approximately 2-3% of the world’s population, regardless of gender or age. It manifests as scaly, itchy and reddened skin. In most cases (approximately 70-80%), psoriatic lesions are mild and do not require systemic treatment.

– The pathogenesis of psoriasis is not yet fully understood. Recent research suggests that the increased immune response responsible for the systemic inflammation seen in this disease may be a consequence of the aforementioned intestinal dysbiosis – points out Urszula Krupa-Kozak.

DIETARY SUPPORT

Attempting to prove this relationship is one of the main tasks of a project just started by scientists from the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn.

– Diet and its components have a very strong influence on the course of psoriasis. Proper nutrition is a method to help counteract complications accompanying this disease, such as metabolic disorders, obesity or diabetes. Through a nutritional intervention using a prebiotic, we want to support the microbiome of our patients – emphasises the researcher.

Scientists have investigated a prebiotic derived from chicory: inulin-type β-fructans, which occurs naturally in onions, garlic, bananas or asparagus. – Numerous scientific studies have shown that it is a prebiotic that beneficially alters the composition and activity of intestinal microbes and alleviates intestinal inflammation. It has also proven itself in patients with coeliac disease, which is what I dealt with in a previous project – says Urszula Krupa-Kozak.

Prebiotics nourish the microorganisms that naturally reside in our digestive tract, mainly in the large intestine. Thanks to prebiotics, the beneficial probiotic bacteria increase their numbers and more actively produce their metabolites, mainly short-chain fatty acids, which have a beneficial effect on the body. These bacterial metabolites show anti-inflammatory effects by influencing the function and activity of immune cells.

– The aim of our study is to determine whether dietary supplementation with inulin-type β-fructans derived from chicory will provide measurable health benefits to patients with psoriasis. We will test whether these benefits result from modification of the composition and activity of the gut microbiota,” the researcher reports.

To achieve this goal, the team led by Dr Urszula Krupa-Kozak will conduct an original, advanced and complex study involving approximately 70 patients with psoriasis who will take the supplement for eight weeks. The study will include, among other things, characterisation of their gut microbiota, assessment of gut barrier function, analysis of selected biomarkers and metabolic parameters, which the researchers suspect will help to elucidate the nature of the interaction between the gut microbiota and the skin, providing clues to the functioning of the gut-skin axis.

– If our hypothesis proves itself and we show that this prebiotic has a beneficial effect on the study parameters, the results of our research will be able to contribute to the development of dietary recommendations that can be used to treat patients with psoriasis – concludes Urszula Krupa-Kozak.

PROJECT LAUNCH

The research is being carried out as part of the project ‘Effect of intestinal microbiota modulation induced by the chicory inulin-type β-fructans on metabolic parameters and biomarkers of the gut-skin axis in chronic skin inflammation’, funded by the National Science Centre (NCN).

The leader of the project is the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn. Partners: the School of Medicine of the University of Warmia and Mazury in Olsztyn (team of dermatologists from the Department and Clinic of Dermatology, Sexually Transmitted Diseases and Clinical Immunology under the direction of Prof. Agnieszka Owczarczyk-Saczonek) and the Institute of Human Nutrition Sciences of the Warsaw University of Life Sciences (team from the Department of Dietetics under the direction of Prof. Ewa Lange).

The amount of funding is more than PLN 2 million. The project is expected to be completed in 2027.

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Vitamin D regulates hundreds of genes and dozens of physiological functions in the human body, including those responsible for immune system activity. Scientists from the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn have just demonstrated that vitamin D in healthy individuals actually helps maintain a state of balance in immune system cells.

– Vitamin D has long been known to have beneficial effects on human health. In our recent studies, we have confirmed that in healthy individuals, vitamin D stabilises the homeostasis of human immune cells and counteracts molecular stress occurring, for example, due to microbial infection or inflammation – emphasises Dr Julia Jarosławska-Miszkiewicz from the Nutrigenomics Team of the IAR&FR PAS in Olsztyn.

– Previously, this knowledge was conjectural, we have confirmed for the first time in a study that vitamin D in a healthy body actually regulates biological functions at the cellular level – adds the nutrigenomics scientist, who studies how the foods we eat (nutri-) interacts with all of our genes (-genomics).

The basis for the study was material taken from 25 healthy people – blood drawn before and after taking the recommended monthly dose of vitamin D (80,000 units). The researcher looked at so-called signal transduction pathways in cells. Cell signalling is part of a complex communication system that regulates cell processes and coordinates cell activity.

– A number of genes in cells, including those of the immune system, are responsible for transmitting the appropriate signal from outside or inside the cell to produce the appropriate molecular effect, i.e. to encode proteins accordingly. I carried out an analysis of 16 such major signalling pathways, assessing a number of biochemical reactions through which this process occurs – says the scientist.

Analysis has shown that vitamin D in healthy immune cells in healthy humans modulates these pathways and thus regulates physiological cell functions such as, for example, growth, differentiation, cell migration or the cell’s response to stress factors.

The results of the described research were published in the International Journal of Molecular Sciences.

Vitamin D – essential for our health

Vitamin D affects the functioning of the entire body. Its most well-known action is to maintain adequate levels of calcium in the body to maintain normal bone structure. Vitamin D is also important for 'training’ the immune system so that it works effectively in case of microbial infections, but also does not overreact in case of possible autoimmune reactions.

Long-term vitamin D deficiency can lead to bone diseases – rickets in children and osteomalacia (soft bones) in adults. It also causes a malfunction of the immune system, leading to, for example, increased susceptibility to infectious diseases or autoimmune diseases.

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More information on nutrigenomics at IAR&FR PAS in Olsztyn and the latest research of the ERA Chair WELCOME2 team can be found on the website: https://welcome2.pan.olsztyn.pl/.

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Fish eggs are among the largest sex cells in the vertebrate world, but the processes and mechanisms within them are not yet fully known. In perch, one of the unknowns is the influence of factors from the parents on the quality of the offspring – the larvae. The answer is being sought by scientists from the Department of Gamete and Embryo Biology of our Institute.

– We know little about parental influence on offspring quality in most domesticated fish species. In the case of perch, no such data are available at all. Therefore, we are looking for an answer to the question of what factors on the part of the female and/or the male make one fish of their offspring qualitatively better and the other worse – explains study leader Dr Daniel Żarski from the Department of Gamete and Embryo Biology of the IAR&FR PAS in Olsztyn.

„PACKAGE” WITH A SET OF EXPERIENCES

Key to understanding these factors is the study of eggs and larvae at the molecular level. Fish eggs are some of the largest sex cells in the vertebrate world – they have a lot of different kinds of molecules in them, including a lot of spare material (mainly in the form of fats and proteins), which allows the fish larvae to continue to develop for some time after hatching. This is because fish in our climatic zone spawn and in most cases abandon their eggs (there is no gestation stage as in mammals or egg-laying as in birds), so such a cell, in order to develop on its own, must be adequately protected and supplied „for the immediate future”.

As in any other cell, there are a number of different molecules in the egg besides the DNA itself. – We looked specifically at the mRNA, where there is encoded information that the mother wants to pass on to her offspring – a set of experiences from a whole year, such as the stress she has experienced or interactions with other fish or predators. All this information is passed on by the mother to the egg so that the offspring, at least initially, are prepared for the problems they may encounter. We call this non-genetic inheritance – says the fish reproductive scientist.

This information is easily modifiable – the mother 'updates’ it every year on the occasion of each reproduction.
– Among other things, precisely because of the factors to which the female has been exposed recently, one year her offspring will be of better quality and the next year they may be of worse quality – adds Daniel Żarski.

Such factors that determine the quality of the offspring – here understood as the ability of the larvae to hatch and to adapt to the rearing conditions – are numerous. Not only on the part of the mother, but also on the part of the father, and they are still not fully known.

ON THE HALFWAY

Daniel Żarski’s team is working on solving this issue, conducting research as part of the project entitled 'Transcriptomic and zootechnical analysis of parental influence on offspring quality in perch, Perca fluviatilis’, funded by the National Science Centre (NCN).

We are halfway through the project. We have already carried out 4 of the 6 planned experiments (plus one additional one), and we have to remember that under our climate conditions we are able to carry out reproductive studies on perch only once a year – in spring, when the fish are spawning. One of the biggest challenges so far has been to carry out an experiment comparing two extremely different phenotypes, i.e. larvae from wild, domesticated fish and their crosses. We are now analysing the collected data, the preliminary results of which seem very promising – the scientist points out.

The researchers still have an experiment ahead of them which is expected to help decipher what causes twin offspring to have different growth potential and, as a result, to be of different sizes.

– Our project is not based on specific hypotheses, but is an exploratory project. In other words, we are trying to understand these mechanisms that we observe, rather than 'squeezing them’ into a top-down framework – emphasises Daniel Żarski.

The project started in 2021 and will last until 2026. The amount of funding is more than PLN 2.8 million. IAR&FR’s partner in the project is the Stanisław Sakowicz Inland Fisheries Institute in Olsztyn.

OBJECTIVE: TO SET THE STANDARDS

According to Daniel Żarski, the knowledge gained through the project’s research will not only contribute to the advancement of science on the topic of perch fish reproduction and larviculture, but may also find applications in aquaculture in the future.

– Perch are the right species to study for several reasons: they are much larger than typical model fish, they have high fecundity, they are a young species phylogenetically, and they have a large and growing breeding potential. Therefore, our overarching goal is to set some standards for creating selection criteria, always much needed by breeders,” explains Daniel Żarski.

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